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1. gt program U CR5000 gt 4 Outputs Scan Interval Select the Scan Interval 5 Finish fa as This is how frequently measurements are made Wiring Wiring Diagram Wiring Text 4 Previous l Next gt Finish Help E i Sm 911 AM Be ol Vlo w o AO a Figure B 3 Selecting the Data Logger Model and Scan Interval in Short Cut 5 The next screen allows you to select the devices you are using to connect with the data logger Prior to creating the program some attention must be given to the model numbers of the anemometers and the weather vane and the thermocouple The type of strain gage must be known along with the gage factor This information can be obtained from the packaging provided with the strain gage 105 9 Sh File Program Tools Available Sensors and Devices Selected progress y CR5000 Sensor Measurement 1 New Open 4 y Sensors 4 CR5000 2 Datalogger J Generic Measurements Geotechnical amp Structural 4 Default mony p 3 Senare Meteorological PTemp_C 4 Outputs Miscellaneous Sensors 5 Finish a Temperature 1 Water 4 5 Calculations amp Control Wiring Calculations Wiring Diagram gt Gi Control ae 4 Ey Devices Wiring Text O am16 32 O Am25T 13 AM32 OD AM416 OD swi2v CR5000 Edit Remove Double click a folder icon to see the sensors in that category Add a sensor by highlighting
2. Figure 3 11 Panel Layout and Location 32 4 Instrumentation 4 1 Introduction The desired output was measured using a data logger and various instruments as described below 4 2 Data Logger Data was collected using a Campbell Scientific CR5000 data logger The data logger was calibrated by Campbell Scientific prior to use An external battery was used to power the data logger in conjunction with a solar panel which was used to charge the external battery The data was stored on a PC card to decrease the number of trips to the site to download data and also to reduce the downloading time During the research the data logger was placed within a sheet metal enclosure box to protect it from wind rain and snow The data logger was programmed to record the strain wind speed and wind direction at one second intervals The data was then post processed to average the wind speeds and associated strains over three second and nine second intervals 33 ree ey Perea ee E ak hak Soke PRS DERT ES Ae vee came wanes ues IAEA Figure 4 1 Campbell Scientific CR5000 Data Logger Figure courtesy of Campbell Scientific Inc Logan Utah 4 3 Solar Panel A Campbell Scientific SP20 solar panel shown in Figure 4 2 was used to charge the CR5000 data logger s external battery so that continuous data records were gathered The panel was oriented to the south to gain maximum sun exposure 34 Figure 4 2 SP20 Solar Pane
3. 1 1 1 1 1 1 1 0 1 0 0 9 0 9 0 8 0 8 0 5 0 5 0 4 0 4 0 3 0 3 0 2 0 2 0 1 0 8 75 Panel B 3s Strain Interval 3s Average Wind Speed 150 8 j 140 ocity mph C Wind Velocity _ E o ti o 5 d Vel Strain ue CN Win K o pa in t o 110 Cr Time seconds Figure 6 12 Time History of Wind Velocity and Strain with Corresponding Cr The time history diagram above is taken from data obtained on 4 14 13 and averaged over a three second interval Table 6 11 Summary of Cr determinations from Figure 6 12 within wind direction tolerance for 3 second rolling averages Cr 3 second Average 11 3 3 6 1 6 1 0 9 8 3 3 1 4 0 9 5 8 2 2 1 2 0 9 4 7 2 1 1 2 0 9 4 3 2 1 1 1 0 7 4 0 1 7 1 1 76 Panel B 3s Strain Interval 3s Average Wind Speed 170 Strain C 150 ot T Strain E so y 140 A 3 y pa 2 o fe v n Wind Velocity 130 d n A ls ls a 1 61 121 181 241 301 361 Time seconds Figure 6 13 Time History of Wind Velocity and Strain with Corresponding Cf The time history diagram above is taken from data obtained on 4 14 13 and averaged over a three second interval 77 Table 6 12 Summary of Cr determinations from Figure 6 13 within wind direction tolerance for 3 second rolling averages Cr 3 second Average 8 4 7 5 5 4
4. 3 Homegroup L WindSolarfinal_20130337 CR5 4 1 201312 54 PM CR5File E e bie j Computer m m o File name y CR5000 PROGRAM FILES CR5 y pl gt gt ABS Units GFAdicunitless ACOS Units BrZero mv V ha Units WS_mph miles hour AND Units WindDir degrees AngleDegrees Units WS_mph 2 miles hour Aral th 5 vrayLengl Units Temp F Deg F ASCII ASIN Define Data Tables ATN DataTable Table2 True 1 ATN2 DataInterval 0 1440 Min 10 Average AvgRun la y AvaSpa a Line 33 Col 26 C Campbellsci SCWin Example CR5 loaded Insert Figure C 3 Opening an Existing Program in the CRBasic Editor 3 Your program will appear in the main window of the CRBasic Editor The first items listed are text Text can be distinguished from Programming information by the apostrophe symbol located in front The first portion of the program is a list of the Variables and their units along with the name of the table which the tables will be stored within Note the last variable in the list Public GFsRaw 7 2 2 2 2 2 2 2 The number 2 corresponds to the gage factor for the strain gages This value can be adjusted in the CRBasic Editor if necessary by simply selecting each gage factor and changing the number 133 CRBasic Editor Example CRS for the CR5000 W O A q File Edit View Search Compile Template Instruction Goto Window Tools Help saenz o Created by Short Cut 2 9 H
5. Declare Variables and Units Public BattV Public FCLoaded Public Plemp C Public CReps Public ZMode Public QBSSMods Public CIndex Public CAvg Public LCount Public Strain 7 Public Vr1000 7 Public GFAdj 7 Public BrZero 7 Public CKnown 7 Public WS_mph Public WindDir Public FS mph 2 ik c GFsRav 7 2 2 2 2 2 2 2 Units BattV Volts Units Plemp_C Deg C Units Strain microstrain Units Vri000 mV V Units GFAdj unitless Units BrZero W V Units WS_mph miles hour Units WindDir degrees Units WS mph 2 miles hour Units Temp F Deg F Define Data Tables DataTable Teble2 True 1 DateInterval 0 1440 Min 10 la r Line 1 Col 1 C Campbellsci SCWin Example CR5 loaded Figure C 4 Strain Gage factors CRBasic Editor Example CRS for the CRSO0O M O O NN a a lola juas File Edit View Search Compile Template Instruction Goto Window Tools Help Tax 120084025 900 Ma CRS000 Created by Short Cut 2 9 1282 Declare Variables and Units Public BattV Public FCLoaded Public Plemp_C Public CReps Public ZMode Public QBSSMode Public CIndex Public CAvg Public LCount Public Strain 7 Public Vr1000 7 Public GFAdj 7 Public BrZero 7 Public CKnown 7 Public WS_mph Public WindDir Public S_mph 2 A Public GFsRaw 7 2 105 2 105 2 105 2 105 2 2 2 Units BattV Volts Units Plemp_C Deg C Units Strain microstrain Units Vri000 mv V Units GFAdj unitless Units BrZero mV
6. For I 1to5 Tf IntS D lt 0 21 Then INT8 D 0 nextIEndProg 145 D Program D 1 Introduction The program that was created and used to obtain the measurements and data provided in this thesis is provided below D 2 Program Call Data Tables and Store Data CallTable Wind6 CallTable Table2 CallTable CalHist CallTable Dat5min NextScan CR5000 Created by Short Cut 2 9 Declare Variables and Units Public BattV Public FCLoaded Public PTemp_C Public CReps Public ZMode Public OBSSMode Public CIndex Public CAvg Public LCount Public Strain 3 Public Vr1000 3 Public GFAdj 3 Public BrZero 3 Public CKnown 3 Public CReps_2 Public ZMode_2 Public OBSSMode_2 Public CIndex_2 Public CAvg_2 Public LCount_2 Public Strain_2 4 Public Vr1000_2 4 Public GFAdj_2 4 146 Public BrZero_2 4 Public CKnown_2 4 Public WS_mph Public WindDir Public WS_mph_2 Public Temp_F Public GFsRaw 3 2 115 2 115 2 115 Public GFsRaw_2 4 2 115 2 115 2 115 2 115 Public Int8 5 Public PulseCh 2 Dim I Units BattV Volts Units PTemp_C Deg C Units Strain microstrain Units Vr1000 mV V Units GFAdj unitless Units BrZero mV V Units Strain_2 microstrain Units Vr1000_2 mV V Units GFAdj_2 unitless Units BrZero_2 mV V Units WS_mph miles hour Units WindDir degrees Units WS_mph_2 miles hour Units Temp_F Deg F Define Data Tables DataTable Wind6 True 1 DatalInterval 0 1 Sec 10 CardOut 0 1 Sample 1 PT
7. Figure B 1 Procedure for Accessing Short Cut within RTDAQ Program 103 3 Once Short Cut has opened you can choose to create a new program or open an existing program In this case we are creating a new program 9 Short Cut Erama File Program Tools Hip Welcome to Short Cut Short Cut will help 1 New Open you generate a datalogger program The basic steps are 1 Create New Open Program 2 Select Datalogger 3 Select Sensors Wiring 4 Select Outputs 5 Finish Compile the Program Click New Program to begin Click Open Program to open an existing Open Progam Short Cut program Finish Help z wi gt A 9 10 AM I eS W e O 5 26 2013 _ Figure B 2 Creating a New Program in Short Cut 4 Select the data logger model you are using The options are CR1000 CR3000 CR5000 CR800 Series and CR9000X For our case we were using a CR5000 Choose a scan interval This tells the data logger the sampling or execution interval In this case a one second interval was desired The units can also be changes to microseconds milliseconds and minutes Once the data logger model and the scan interval have been selected click the next button at the bottom of the screen 104 9 Short Cut CR5000 CACampt File Program Tools Help Progress Datalogger Model 1 New Open 2 Datalogger 3 Sensors Select the Datalogger Model for which you wish to create a
8. Sample 1 Strain S IEEE4 Sample 1 Strain 6 IEEE4 Sample 1 Strain 7 IEEE4 Sample 1 WS_mph FP2 Sample 1 WindDir FP2 Sample 1 WS_mph_2 FP2 Sample 1 Temp_F FP2 EndTable lu DataTable Table2 True 1 DataInterval 0 1440 Min 10 Minimum 1 BattV FP2 False False EndTable Calibration history table DataTable CalHist NewFieldCal 10 SampleFieldCal EndTable Main Program BeginProg E lize calibration variables for r Bridge Strain 3 vire 350 ohm vith 4WFBS350 TIM measurement Vri000 CIndex 1 CAvg 1 CReps 7 For LCount 1 To 7 GFAdj LCount GFsRaw LCount Next Load the most recent calibration values from the CalHist table te r Line 39 Col 2 C Campbellsci SCWin Example CR5 loaded Figure C 9 CardOut Instructions 8 Type in the words CardOut 0 1 The O corresponds to the stop ring and the 1 value corresponds to the size of the table Right click on the value CardOut for an explanation of what each of these parameters means 138 CRBasic Editor Example CRS for the CR5000 LS w File Edit View Search Compile Template Instruction Goto Window Tools Help AAA EEE NAL Units Temp F Deg F Define Data Tables DataTable Tablel True 1 10 eS PIEEE4 Sample 1 Strain 2 IEEE4 Hoa Sample 1 Strain 3 IEEE4 HEndif Ie Sample 1 Strain 4 IEEE4 Hf 7 Sample 1 Strain S IEEE4 amp S
9. x10 pad of concrete pavers to distribute the load from the panels over the existing precast concrete double tee roof framing system The uplift force on each of the panel legs was resisted by sand bags which were provided in lieu of a direct connection between the panels and 31 the existing roof structure Once the panels were placed in the location shown in Figure 3 11 below 50 lb sand bags were stacked on the ends of the 2x6s until the desired hold down force was achieved Upon installation of the faux solar panels it became clear that the height of the stacked sand bags could influence the air flow surrounding the faux solar panels particularly panel A In an effort to reduce the changes in the air flow the height of the sand bag stack was limited to the height of the top of the parapet However for panel A this was approximately half its height Three anemometers were used to measure the wind speed at different locations One of the anemometers was positioned below the shear layer the second at the assumed location of the shear layer and a third well above the assumed location of the shear layer 240 LB SAND PANEL B 2 x4 PLYWD S5LB SAND BAG O EA LEG aun Ee Ure SE END OF PANEL a o 2 0 2 0 e a ae 4 0 MAX PS Sa a amp Pd ai e Rese e 8 Ree dd d 50LB SAND A BAG EA roteto VARIES LEGSE END x A E 7 OF PANEL PAVERS
10. 1 03001 Wind Speed amp Direction Sensor 4 2 QB Strain 3W 350 2 of 7 Strain 2 Wiring L 03002 Wind Speed amp Direction Sensor Vr1000 2 Wiring Diagram a pean eal puras le 43 QB Strain 3W 350 3 of 7 Strain 3 SS L 0344 0348 Wind Speed amp Direction Sensor Vr1000 3 Q 05103 Wind Speed amp Direction Sensor 4 4 QB Strain 3W 350 4 of 7 Strain 4 Q 05106 Wind Speed amp Direction Sensor Vr1000 4 F ceria hake rents pai 4 5 QB Strain 3W 350 5 of 7 Strain 5 Q CS800 Wind Speed amp Direction Sensor Vr1000 5 L NRG 200P Wind Direction Sensor 4 6 QB Strain 3W 350 6 of 7 Strain 6 L NRG 40 Wind Speed Sensor vr1000 6 L WindSonic4 SDI 12 Two Dimensional Ultrasonic Wind Sensor E Miscellaneous bal 4 7 QB Strain 3W 350 7 of 7 Strain 7 Ea Temperature 2 Vr1000 7 Water Calculations amp Control CR5000 Edit RM Young Wind Sentry Wind Speed and Direction Sensor Units for Wind Speed meters second kilometers hour miles hour knots Units for Wind Direction degrees Remove Ls Previous f Next gt Finish Help a 11 22 AM 5 26 2013 a i ll D Figure B 8 Adding Anemometers and Weather Vanes 11 To add the weather vane and anemometers select the Meteorological tab under the Available Sensors window 12 Next select Wind Speed amp Direction There are several options available to choose from Single click on each sensor listed to see a picture of the 110 device
11. 1 61 121 Time seconds Figure 6 5 Time History of Wind Velocity and Strain with Corresponding Cr The time history diagram above is taken from data obtained on 4 14 13 and averaged over a three second interval E un a o o o Wind Velocity mph 62 C Table 6 4 Summary of Cf determinations from Figure 6 5 within wind direction tolerance for 3 second rolling averages Cr 3 second Average 11 9 2 1 1 1 0 4 9 2 2 1 0 9 0 4 6 6 1 9 0 8 0 3 5 6 1 8 0 7 0 2 5 6 1 6 0 7 0 1 3 8 1 5 0 6 3 4 1 5 0 5 2 9 1 4 0 5 Panel B 3s Strain Interval 3s Average Wind Speed Strain E 160 e Strain ue E 8 5 Wind Velocity mph C Wind Velocity p w o 120 Cr uol b r a a dl Erro al I 181 241 1 61 121 301 361 Time seconds Figure 6 6 Time History of Wind Velocity and Strain with Corresponding Cr The time history diagram above is taken from data obtained on 4 14 13 and averaged over a three second interval 64 Table 6 5 Summary of Cr determinations from Figure 6 6 within wind direction tolerance for 3 second rolling averages Cr 3 second Average 6 8 2 0 1 3 0 7 6 6 2 0 1 2 0 7 5 0 2 0 1 2 0 7 4 2 2 0 12 0 5 4 0 1 8 1 1 0 4 3 7 1 8 1 1 0 4 2 9 1 7 0 9 0 4 2 8 1 6 0 9 0 4 2 7 1 6 0 9 0 3 23 1 5 0 9 0 2 2 3 1 5 0 8 0 2 2 3 1 5 0 8 0 1 2 0 1 3 0 7 0 1 170 Strain ue g t o 120 110 Panel B 3s Strain Interval
12. 5 3 4 4 3 6 3 1 2 7 2 6 2 4 1 9 1 6 1 6 1 5 1 5 1 3 1 2 12 1 2 1 0 1 0 1 0 1 0 1 0 0 9 0 9 0 9 0 9 0 8 0 8 0 8 0 6 0 5 0 5 0 4 0 3 0 2 0 2 0 8 0 6 78 Figures 6 14 through 6 16 are time history diagrams plotted over a 400 second time interval for a wind direction 45 degrees from the perpendicular axis of the panel or 225 degrees as measured 215 to 235 degrees The corresponding Cr values summarized in Tables 6 13 through 6 15 have been filtered for the same wind direction Panel B 170 Strain ue E Wind Velocity Wind Velocity mph 120 Mos E OA lo ae lee 1 61 121 181 241 Time seconds 361 Figure 6 14 Time History of Wind Velocity and Strain with Corresponding Cf The time history diagram above is taken from data obtained on 4 22 13 and averaged over a three second interval 79 Table 6 13 Summary of Cr determinations from Figure 6 14 within wind direction tolerance for 3 second rolling averages Cr 3 second Average 11 1 6 9 6 7 dl 3 6 3 0 2 8 2 6 2 1 1 9 1 8 1 8 1 6 1 4 1 4 1 4 1 3 1 3 1 2 1 1 1 1 1 1 0 9 0 9 0 9 0 9 0 8 0 8 0 8 0 8 0 7 0 7 0 7 0 7 0 7 0 6 0 6 0 5 0 5 0 5 0 5 0 4 0 4 0 4 0 4 0 4 0 3 0 3 0 3 0 2 0 2 0 2
13. LIST OF FIGURES Figure 2 1 Principles of Wind Flow against a Bluff Body coocoononcccnoncccnoncccnoncconancnnnnncnnnnncnnnnnos 9 2 2 Smoke Visualization Used in the Boundary Layer Wind Tumnel ooooonnoccnnncccnnoncccnn 12 2 3 Solar Collector Mounted on a Building with a Flat Roof and a Parapet 13 2 4 Design GCp Values Published by SEAOC August 2012 ooooocnnccnoccciccnnocncooncnoncnnnos 18 2 5 Figure 29 91 from SEAOC Document A Haewaewan 19 3 1 Location of the Solar Panels on the Event Center Building oooonooccnnoncccconccinoncninns 23 3 2 Location of the Solar Panels on the Event Center Building oooonoocccnoncccnoncccnoncninns 23 3 3 Location of the Solar Panels on the Event Center Building ooonooccnnonccncnaccn nncninno 24 3 4 Site Location of the University of Colorado Denver oooocconoccnococioccconocannnonanonancnnonnnos 25 3 3 Panel A Construction Overview asen lila 27 3 6 Panel B Construction OVER 28 Anas A eecie teres meena Aaa att tee ste 28 3 8 Panel Frame Connection Details at the Diagonal Tension Ties 0 0 0 0 eeeeeeeeeeeees 30 3 9 Panel Frame Connection Details in the Short Dimension oooonoocccnoncncnoncnononcninananinns 30 3 10 Close Up View of Short Direction Panel Frame Connection Details 31 3 11 Panel Layout ame LA E A ee aes 32 4 1 Campbell Scientific CR5000 Data Logger oooooocnnococonocnconnnncnonanononcnconncnonnnccnnnncnonnnanos 34 4 2 SP20
14. Radu 1986 11 Figure 2 2 Smoke Visualization Used in the Boundary Layer Wind Tunnel Photo used from the 1986 Radu study Radu et al 1986 used with permission In fact the study determined through the testing of numerous arrays with many collectors mounted in the longitudinal direction of the wind that the panels prevented flow re attachment on the surface of the roof The dominant resultant force acting on the surface of the panels was uplift and the panels caused increased turbulence over the entire roof area The research provided values of pressure coefficients that were measured across the panels that varied from 0 7 to 0 9 Where a positive force coefficient represents pressure acting toward the surface of the panel and a negative pressure coefficient is used where the pressure is acting away from the surface of the 12 panel The study concluded that more testing was necessary particularly with respect to varying exposure categories modeled in the wind tunnel Since that time research has continued in boundary layer wind tunnels Figure 2 3 below depicts the many factors that have been considered in previous wind tunnel studies which affect results of the model including building height z the height of the panel a the slope of the roof surface the slope of the panel 0 the distance the panel is located with respect to the windward edge of the building c as well as the wind speed and direction The presence an
15. The basic equation that most design engineers in the U S use to calculate wind velocity pressure is provided in ASCE7 10 EQ 27 3 1 This equation determines the velocity pressure with respect to the height above the ground z as follows qz 0 00256K K KqV 1 2 These two equations are similar however ASCE7 10 equation 27 3 1 uses a factor of 0 00256 to account for the conversion from fluid to air at sea level K is the velocity pressure coefficient with respect to the height z above the ground surface K is a topographic factor to account for wind speed up at hills and escarpments and Kg is a wind directionality factor Once the designer determines the appropriate velocity pressures ASCE7 10 has prescriptively developed methods to calculate the design wind load acting on various building components The velocity pressure is adjusted further for gust effects and also for enclosed spaces such as buildings internal and external pressure coefficients These internal and external pressure coefficients were developed for the most part through many wind tunnel studies the results of which produced the design curves used by ASCE7 The design methods used by ASCE7 consider the aerodynamics of wind forces as they interact with a bluff body Figure 2 1 below illustrates wind flow over a low rise buildings with flat roofs and a parapet along the roof edge As wind flows toward the building it eventually impacts the windward face and forms a separ
16. This allows the user to average the data over a desired interval To capture all the data select Sample Note that the first strain gage now appears in the Selected Outputs window on the left hand side of the screen The Selected Outputs window gives you a summary of the Sensor the Measurement and the type of processing you have chosen the output label and the desired units Short Cut arbitrarily names the table to which your data is stored as Table 1 You can rename the table to something else if you wish 118 9 Short Cut CR5000 C Campbellsci SCWin untiiedsew Scan Interval gt Seconds Sa eon MT File Program Tools Help Progress Selected Sensors Selecte uts Sensor Measurement Average Tal 3 rae 1 New Open 2 Datalogger Battv Every so Minutes y 3 Sensors PCCard 4 Outputs 1 QB Strain 3W 350 1 of train 1 Sample SC115 CS 1 O to USB Flash Memory Drive 5 Finish vo Stevi Sensor Measurement Proce Output Label 4 2 QB Strain 3W 350 2 of 7 Strain 2 Tze QB Strain 3W 350 Strain 1 sample Strain 1 microstrain Wiring Vr1000 2 WindVector Wiring Diagram 4 3 QB Strain 3W 350 3 of 7 Strain 3 Wiring Text Vr1000 3 4 4 QB Strain 3W 350 4 of 7 Strain 4 vr1000 4 4 5 QB Strain 3W 350 5 0f 7 Strain 5 Vr1000 5 4 6 QB Strain 3W 350 6 of 7 Strain 6 Vr1000 6 47 QB Strain 3W 350 7 of 7 Strain 7 Vr1000 7 4 03001 WS_mph WindDir 03101 WS_mp
17. WindSolar_6Gages SCW SCW File 23 Homegroup af m Filename SELEENA EE Save as type Short Cut programs SCW QB Strain 3W 350 3 Strain 3 Vr1000 3 CR5000 4WFBS350 3 A Common H A Common L B G 7 m 55 PM co 289 5 21 2013 Figure B 22 Saving the Program 29 Once the program has been saved under the desired name and in the desired location a message will appear which says The program was created successfully Do you wish to send the program to the data logger You can either choose to send the program to the data logger at this time click Yes or if editing is required in CRBasic Editor then select No To send data to the data logger the trend net cable must be attached to the appropriate port labeled on the data logger and into a USB port on your computer Note that prior to using the trend net cable the driver must be installed on your computer The CD for the device driver is located in a plastic bag with the cable inside of the data logger If for 125 some reason the user chooses not to send the program to the data logger at this time you can send upload and send the program within RTDAQ 30 To open and send the program to the data logger first open the RTDAQ software on your computer The user must first connect with the data logger To connect with the data logger install the trend net cable must be used to transfer the data Once this cable has been installed you will notice that
18. in ft Characteristic height equal to min A 1 ft sin m except when evaluating toward a building edge unobstructed by panels then 4 0 1a for that panel in that direction in ft Mean parapet height above adjacent roof surface in ft Chord length of solar panel in ft Width of overall building on longest side in ft Width of overall building on shortest side in ft Panel chord length factor equal to 1 0 for lt equal to 0 6 0 061 for gt 15 but shall not be less than 0 8 For 5 lt 15 apply y only to 15 35 GC figure values and prior to interpolating Parapet height factor equal to 1 0 for hy lt 4 ft equal to the smaller of 0 25 A and 1 3 for ha gt ft Angle of plane of roof from horizontal in degrees Angle of plane of panel to roof in degrees Figure 2 5 Figure 29 9 1 from SEAOC Document Part 2 of SEAOC Document Wind Loads on Low Profile Solar Photovoltaic Systems on Flat Roofs published in Draft format on March 28 2012 SEAOC 2012 used with permission 19 2 6 Conclusions Although the amount of research that has been previously conducted is abundant the results of those tests are proprietary the data measured from them is not available to the public or to code writers for publication SEAOC has recently commissioned a Wind Subcommittee on Solar Photovoltaic Systems to publish the data obtained from these numerous wind tunnel studies and provide design pressure coeffic
19. 0 2 0 2 0 1 0 1 80 Panel B 3s Strain Interval 3s Average Wind Speed 160 50 155 th o Strain C E a _ 50 y a gt va 8 W T su oO wn gt 130 Wind i on 125 g H 2 20 120 TE y E F 10 115 110 mA A Ma all a al I i o 1 61 121 181 241 301 361 Time seconds Figure 6 15 Time History of Wind Velocity and Strain with Corresponding Cf The time history diagram above is taken from data obtained on 4 22 13 and averaged over a three second interval Table 6 14 Summary of Cr determinations from Figure 6 15 within wind direction tolerance for 3 second rolling averages Cr 3 second Average 15 4 7 5 6 8 3 9 3 8 3 7 3 5 3 2 2 9 2 4 22 2 1 1 7 1 6 1 4 1 4 1 3 1 3 1 2 1 1 0 8 0 8 0 8 0 8 0 7 0 6 0 6 0 6 0 5 0 5 0 4 0 4 0 4 0 3 0 3 0 3 82 Panel B 4 14 13 3s Strain Interval 3s Average Wind Speed O I I Y ASA 1o II Nt A A Strain C Strain E 140 SA 5 Wind Velocity U i Me 4 ic Al A a Cr 20 1al 121 181 241 Time seconds L al i ls Wind Velocity mph Figure 6 16 Time History of Wind Velocity and Strain with Corresponding Cr The time history diagram above is taken from data obtained on 4 30 13 and averaged over a three second interval Cr 83 Table 6 15 Sum
20. 0 6 to 2 2 for the 3 second rolling average It is observed that the wind velocity is highly variable over the relatively short time duration The wind velocity and measured strain are less variable when an alternative averaging interval is selected In Figure 6 2 a 9 second rolling average was used to smooth out the variability in the data plot Note that the Cr values in Table 6 2 reflect that there is less variation than in Table 6 1 The Cr values in Table 6 2 for the 9 second averaged data plotted in Figure 6 3 ranged from a minimum Cf of 0 1 toa maximum value of 13 8 however the majority range from 0 5 to 1 8 We note that Cpr values as high as 10 are reported to often occur and up to 20 have occasionally been measured however these values are associated with corner 85 vortices Holmes 2007 This trend appears to also be correct for solar panels located in the shear layer near the edge of a building with a flat roof In Tables 6 1 through 6 8 the force coefficients for the wind perpendicular to the face panel are summarized Two of the values were extremely high and their validity was questionable These values were 18 7 and 17 2 found in Table 6 1 and 6 7 respectively Particular consideration was given to the validity of the Cr values that were calculated Because Cr is determined from the ratio of measured force divided by the force due to the velocity pressure the squared velocity term is always in the denominator of the calcul
21. 14 2012 AAWE Ft Collins CO Finnemore E John Franzini Joseph B 2002 Fluid Mechanics with Engineering Applications 10th Ed McGraw Hill Inc New York Harris J S Dowds E K Rutz F R 2013 Results from Wind load on solar panel experiment Proceedings of the 12 Americas Conference on Wind Engineering Seattle WA June 16 20 2013 AAWE Ft Collins CO Holmes John D 2001 Flow patterns and mean pressure distributions Wind Loading of Structures oe Edition Taylor and Francis New York N Y 180 Perlin John 2004 The Silicon Solar Cell Turns 50 http www nrel gov education pdfs educational_resources high_school solar_cell_histo ry pdf gt accessed June 30 2013 96 Radu A Axinte Elena Theohari Christina 1986 Steady Wind Pressures on Solar Collectors on Flat Roofed Buildings Journal of Wind Engineering and Industrial Aerodynamics 23 249 258 SEAOC Solar Photovoltaic Systems Committee 2012 Wind design for low profile solar photovoltaic arrays on flat roofs SEAOC PV2 2012 Structural Engineers Association of California Sacramento August 2012 Solar Cookers International Network 2012 Horace de Saussure and his Hot Boxes of the 1700 s lt http solarcooking org saussure htm gt accessed November 21 2012 Stathopoulos T Zisis I Xypniton E 2012 Wind loads on solar collectors A review Proceedings of ASCE Structures Congre
22. 3 2 8 1 1 0 5 0 3 2T 1 0 0 5 0 2 2 4 1 0 0 5 0 2 2 3 1 0 0 4 0 1 2 2 1 0 0 4 0 1 3s Strain Interval 3s Average Wind Speed 155 150 145 140 t in t o Strain ue Wind Velocity K in 120 115 110 Cr all P hte L 181 241 Time seconds Figure 6 9 Time History of Wind Velocity and Strain with Corresponding Cp The time history diagram above is taken from data obtained on 4 14 13 and averaged over a three second interval 70 5 8 8 Wind Velocity mph 8 8 10 C Table 6 8 Summary of Cf determinations from Figure 6 9 within wind direction tolerance for 3 second rolling averages Cr 3 second Average 9 1 2 4 1 3 0 6 9 0 2 2 1 2 0 5 7 5 Did 1 2 0 5 5 1 2 1 1 1 0 5 4 6 1 9 1 0 0 5 4 0 1 9 1 0 0 3 4 0 1 7 0 9 0 2 3 7 1 7 0 9 0 2 2 9 1 6 0 8 0 2 2 9 1 6 0 8 0 1 2 8 1 4 0 8 0 1 2 7 1 4 0 8 2 7 1 3 0 7 2 6 1 3 0 7 In Figures 6 10 through 6 13 the time history diagrams have been plotted over a 400 second time interval for a wind direction 20 degrees from the perpendicular axis of the panel 150 to 170 degrees The corresponding Cr values summarized in Tables 6 9 through 6 12 have been filtered for the same wind direction Panel B 4 14 13 3s Strain Interval 3s Average Wind Speed 165 _ 50 A OA a cal AN 45 A A A NPA O O AA o 145 125 Strain E 35 1
23. 4 1 3 1 3 102 1 2 1 1 1 1 1 0 1 0 1 0 0 9 0 9 0 8 0 8 0 8 0 7 0 7 0 7 0 7 0 7 0 6 0 6 0 6 0 6 0 5 0 5 0 5 0 5 0 5 0 4 0 4 0 3 0 2 0 2 0 2 0 1 0 1 0 1 0 1 0 1 Additional time histories are plotted below in Figures 6 4 through 6 9 Following each time history plot the filtered CF values for the 180 degree wind direction are summarized in Tables 6 3 through 6 8 59 Panel B 3s Strain Interval 3s Average Wind Speed 140 3 135 E i 5 Strain E 08 Y G7 Wind Velocity gL sg 125 20 120 VW y 115 Cr 110 at ss il A hil l i a as ii o 1 61 121 181 241 301 361 Time seconds Figure 6 4 Time History of Wind Velocity and Strain with Corresponding Cp The records above were taken from a different time record on 4 14 13 and averaged over a three second interval 60 Table 6 3 Summary of Cf determinations from Figure 6 4 within wind direction tolerance for 3 second rolling averages Cr 3 second Average 8 6 1 5 0 9 0 4 6 5 1 4 0 8 0 4 5 8 1 3 0 8 0 4 4 5 1 2 0 7 0 3 3 3 1 1 0 5 0 2 2 4 1 0 0 5 0 2 2 4 1 0 0 5 0 2 2 4 1 0 0 5 0 1 23 1 0 0 5 0 4 2 1 1 0 0 5 0 4 1 7 1 5 0 5 0 4 Panel B 3s Strain Interval 3s Average Wind Speed 160 155 STRAIN E 150 A 145 w 3 STRAIN C c 135 pd H 130 WIND VELOCITY 125 lu TIRE
24. Complete Cancel Wizard Help Figure B 24 EZSetup Wizard for Connecting to the Data Logger 32 The first step is the Communication Setup Once you are in this window select the Data Logger Type and name from the list In this case the CR5000 was used as shown below in Figure B 25 Ezsetup Wizard CR5000 CR5000 Progress Datalogger Type and Name Introduction Select the datalogger type and enter a name for your datalogger Communication Setup Datalogger Name CR5000 Datalogger Settings Setup Summary Communication Test f Click Next to continue Datalogger Clock Send Program Wizard Complete 4 Previous l Next gt Cancel Datalogger Help Figure B 25 Selecting the Data Logger for the Communication Setup 127 33 Once the appropriate data logger has been selected the wizard will prompt you for the Connection Type In this case we are using the trend net cable to direct connect to the data through the RS32 port r EZSetup Wizard CR5000 CR5000 Progress Connection Type Introduction Select the mode of communication that will be used for this datalogger 2 Communication Setup A direct connection consists of a datalogger IP Port OU with an RS 232 port connected to the serial or i port on the computer If the datalogger has Datalogger Settings RFSS AF IX only a CS 1 0 port then the connection is iis Non PakBus through an
25. Data Interval in CRBasic Editor eee 136 C 8 Editing the Data peca ia 137 C 9 Card Out SU NONS de 138 C 10 EAU A o do 139 C 11 Editing the Differential Chamel 0iii eine een eee 140 xviii 1 Overview 1 1 Introduction Overtime humankind has become dependent on electricity the main source of which is generated from fossil fuels As time has passed and our knowledge has increased we have learned how the combustion of coal and other means of energy production have contributed to negative impacts on our ecosystem Because of this society has become increasingly interested in developing alternative methods of energy production Solar collectors have become a viable alternative source of energy for many commercial and residential buildings An attractive location for mounting solar panels is on the roof of a structure Typically solar panels would be placed in a location and orientation in which to maximize their exposure to the sun and thus collect the most solar energy Because of the placement of the panels on the roofs of buildings and on the ground surface the panels themselves are subjected to environmental phenomena such as wind and snow loads The interaction between the wind load the solar panels and frames to which they are mounted produce significant forces on roof structure to which they are attached The design engineer must be consider these forces not only for the design of the solar panels but also for the frames to which t
26. Di Vr1000 5 O NRG 200P Wind Directia Strain 6 A sca ne on Se vr1000 6 WindSonic4 SDI 12 T EA Miscellaneous Sensors piani ij Temperature RM Young Wind Sentry Wind Speed and Direction ERGO Water Sensor Calculations amp Control Units for Wind Speed meters second CR5000 kilometers hour miles hour knots Units for Wind Direction degrees Cx z Finish Help Pr fie ull 5 Figure B 9 Properties Menu for the Wind Speed and Direction Sensor 14 Next select the units which you would like the program to record the wind speed There is a drop down menu to the right of the Wind Speed box If 111 you wish to record the wind speed in miles per hour simple press the drop down arrow and select miles hour Short Cut CR5000 C Campbellsci SCWin untitled scw Scan Interval 1 0000 Seconds File Program Tools Help Available Sensors and Devices Selected Progress q A 1 A ana gt aero edad 03001 Wind Speed amp Direction Sensor Version 2 9 Moasurement 2 Datalogger gt Relative Humidity amp Temper Properties wiring A Soil Moisture Leumit pp Sena Solar Radiation Wind Speed wS_ms Sa aaa PTemp_C 4 Outputs a y Wind Speed amp Direction j aS matess seconl Wi Strain 1 5 Finish L 014A Wind Speed Senso Wind Direction WindDir kilometers hour vr1000 1 a 024A Wind Direction Sel miles hour aes 03001 Wind Speed Dir knots Wiring Q 03002 Wind Spe
27. Editor it can no longer be opened in Short Cut It is best to add all devices used and generate a wiring diagram in Short Cut prior to opening and editing the program in CRBasic Editor Assess the CRBasic Editor through the RTDAQ software 115 19 To add a Thermocouple select the Temperature tab under the Available Devices and Sensors Window The Type T thermocouple which was provided with the data logger was used in this instance Once the Type T thermocouple has been selected from the available options press the right arrow icon to the right of the Available Sensors and Devices window O Short Cut CR5000 C Campbellsci SCWin untitiedscw Scan Interval 1 0000 Seconds File Program Tools Help Available Sensors and Devices Selected Lido Q 05106 Wind i j val pe ind Speed amp Direction Sensor Sensor Measurement q 1 New Open L 05305 AQ Wind Speed amp Direction Sensor ES PTemp_C 2 Datalogger L 27106T Wind Speed Sensor Q CS800 Wind Speed amp Direction Sensor 4 1 QB Strain 3W 350 1 of 7 Strain 1 3 Sensers NRG 200P Wind Direction Sensor Vr1000 1 4 Outputs L NRG 40 Wind Speed Sensor 4 2 QB Strain 3W 350 2 of 7 Strain 2 5 Finish gt Q WindSonic4 12 Two Dimensional Ultrasonic Wind Sensor vr1000 2 43 QB Strain 3W 350 3 of 7 Strain 3 Wiring Y Chromel constantan Thermocouple Vr1000 3 Wiring Diagram lA 105T copper constantan Thermocouple 44 QB Strain 3W 35
28. Figure 6 1 is provided in Table 6 1 The force coefficients in Table 6 1 were calculated from three second rolling averages as mentioned above The numerical values for strain plotted in the following figures are irrelevant because all of the Cr values were calculated from forces determined from changes in strain 54 Panel B 4 14 13 3s Strain Interval 3s Average Wind Speed 165 50 STRAIN E a 145 45 ira bel Ur le tr yr 125 E STRAIN C 105 WIND VELOCITY y WIND VELOC co w 25 mn un 20 Strain ue 45 Wind Velocity mph 1 61 121 181 241 301 361 Time seconds Figure 6 1 Wind Velocity Strain and Calculated Cr Values from 4 14 13 Data C The values were taken from a selected record averaged using a 3 second rolling average 55 Table 6 1 Summary of Cf determinations from Figure 6 1 within wind direction tolerance for 3 second rolling averages Cr 3 second Average 18 7 2 1 1 3 0 6 9 9 2 0 1 3 0 6 5 2 1 9 1 2 0 5 4 2 1 9 1 1 0 5 3 8 1 9 1 0 0 5 3 8 1 9 1 0 0 4 3 1 1 9 0 9 0 4 2 8 1 7 0 8 0 3 2 7 1 6 0 8 0 3 2 7 1 6 0 8 0 3 2 6 1 6 0 8 0 2 2 5 1 5 0 7 0 2 2 4 1 4 0 7 0 1 2 2 1 4 0 7 2 1 1 3 0 7 The wind direction data over the same time 400 second time history depicted above has been plotted below in Figure 6 2 The Cr values calculated using the 3 second averaged wind velocity from all directions are plotted along the x axis for comparison with Figure 6 1 to
29. Sample 1 Strain 4 IEEE4 3 Sample 1 Strain S IEEE4 IntUnits Al Sample 1 Strain 6 IEEE4 Sample 1 Strain 7 IEEE4 y fs Sample 1 WS_mph FP2 A Sample 1 MindDir FP2 Ey Sample 1 WS_mph_2 FP2 a Sample 1 Temp_F FP2 EndTeble lt lt DataTable Table2 True 1 a DataInterval 0 1440 Min 10 o Minimum 1 BattV FP2 False False EndTable hg gt gt Calibration history table DataTable CalHist NewFieldCal 10 ABS SampleFieldCal ACOS EndTable peon AND Nein Program AngleDegrees Be A04 alize calibration variables for aoe Quarter Bridge Strain 3 vire 350 ohm vith 4WFBS350 TIM measurement Vr1000 ASIN CIndex 1 CAvg 1 CReps 7 ATN For LCount 1 To 7 ATN2 GFAdj LCount GFsRav LCount Average ER AygRun la P AvaSpa as Line 38 Col 7 C Campbellsci SCWin Example CR5 loaded Insert Figure C 7 Data Tables and Editing the Data Interval in CRBasic Editor 6 Below the Table name and Data interval is a list of all the Sensors Since we chose to post process the data when creating the program in short cut the word Sample appears prior to each Sensor If the user decided to record only the average value the maximum value minimum value etc that could be changed at this location Simply change the word Sample to Average or whatever processing type is desired After the word Sample there are three values in parenthesis 1 Sensor Label data type Note that the data type fo
30. Solar Panel Used to Power the CR5000 Data LoggeT ooooococnnncccnnccccnoncninnncnos 35 4 3 Strain Transducer siii 36 4 4 Strain Transducer Calibration Set Up cooococnnocccnonccononccononcnononnnononanononcnonnnnncnnncncnnnnnos 37 4 5 Calibration Curve for Strain Transducer Acuna dabas 37 4 6 Calibration Curve for Strain Transducer B ooconnncccnnnncccnoncncnoncnononcnonnncnononanononaccnnnnnos 38 4 7 Calibration Curve for Strain Transducer Coooooonnnncnocaninnnnonncconanannnonnnono nono nonanononn nono ncnns 38 4 8 Calibration Curve for Strain Transducer D ooonoccnnccinccnnocononononnnonnncnnncnononanncnnnncnn conos 39 4 9 Calibration Curve tor Strain Transducer Erica ci nd 39 4 10 Calibration Curve for Strain Transducer F ooooconccccnnucccconcnononcnononcnnnnnccononanononacinnnnnos 40 4 11 Strain Transducer Instrumentation Plan cee eee eeseceseceeeeeeseeceaeceseeeeeeeeaeeeaeens 41 4 12 RM Young 3101 ATE momen da bici 42 4 13 Overview of Anemometer and Vane Installation onncnnnncnnccnnnonoonononccannnonnncnnnonns 43 5 1 Schematic Diagram of Wind Interaction at Panel B oooocnnccnnnccnocanoconannninanonanonononnnos 46 XIV 5 2 Schematic Diagram of Wind Interaction with Panel A ooo ee eeeeeeeeeeneeeneeeeeetees 46 5 3 Schematic Diagram of Forces Acting on the Panel Surface and Frame 47 5 4 Schematic Time History Diagram of Wind Velocity and Strain eee eeeeeeeee 50 5 5 Filtered Wind Direction for Cf Calc
31. a significant period of time before the codification process is complete the committee published Figures 2 4 amp 2 5 below to provide guidance and design values that can be used in combination with the equations provided in ASCE7 05 or ASCE7 10 The design procedure outlined in Figure 4 below is valid for solar panels mounted on flat roofed buildings with a tilt angle between 2 and 10 and a height h greater than 10 For tilt angles less than 2 basically flat the uplift pressures determined from the ASCE7 10 components and cladding methods are allowed The document also offers guidelines for placement of panels with relation from the roof s edge and there are several adjustment factors included for array edge increase parapet height and chord length The basic equation to compute the velocity pressure is P qntGCrn 13 15 Where qn velocity pressure at mean roof height and GC combined net pressure coefficient for solar panels It was observed that the values for the net pressure coefficients acting on the face of the solar panels GC was significantly greater than the external pressure coefficients provided in Figure 30 8 1 in ASCE7 10 because they are distributed over a significantly larger distance than 0 4h where h is the height of the building or 10 of the least horizontal dimension which is used in ASCE7 for low rise buildings The committee determined that the distance a length of horizont
32. and the model number in the window at the bottom of the screen In this case a RM Young 3001 Wind Speed amp Direction Sensor was used along with two additional anemometers Select the 03001 Wind Speed amp Direction Sensor first and then press the right arrow button to the right of the window 13 Select the 03001 Wind Speed amp Direction Sensor first and then press the right arrow button to the right of the window The properties menu will open for the anemometer and weather vane Short Cut CR5000 C Campbelisci SCWin untitled scw Scan Interval 1 0000 Seconds o pS File Program Tools Help Available Sensors and Devices Selected Progress z ae i a 03001 Wind Speed amp Direction Sensor Version 29 Measurement 2 Datalogger A Relative Humidity amp Temper Properties wiring pce E Soil Moisture Battv Sensors m 8 Ou 4 ine pee urection Strain 1 5 Finish L 014A Wind Speed Senso Wind Direction WindDir degrees vr1000 1 Q 024A Wind Direction Sel Q 03001 Wind Speed amp Di Strain 2 Wiring Q 03002 Wind Speed amp Dirt Vr1000 2 Wiring Diagram 03101 Wind Speed Sensi Strain 3 e 13 03301 Wind Direction Sel Wiring Text D 034A 0348 Wind Speed 8 Vr1000 3 Q 05103 Wind Speed amp Dirt Strain 4 Q 05106 Wind Speed amp Dire Vr1000 4 L 05305 AQ Wind Speed 8 strain 5 L 27106T Wind Speed Sel Q CS800 Wind Speed amp
33. being part of my graduate committee but also for the financial assistance provided for the calibration and repair of the data logger Next I would like to thank Tom Thuis Jac Corless Denny Dunn and Eric Losty of the Electronic Calibration and Repair Lab at UCD for the many hours and late nights spent calibrating strain transducers fabricating steel components and diagnosing and repairing glitches in the testing equipment Each of you is asset to UCD and certainly to this project To the Auraria Higher Education Campus Facilities Department thank you for providing access and allowing us to conduct our research on the Events Center Building and to Pete Hagan for the prompt support To Mick Harris and Andy Andolsek I would like to express the sincerest gratitude for your help constructing the solar panels and carrying them to the roof of the PE building along with Vv many sand bags My freshly injured back would also like to thank you I would also like to gratefully acknowledge my boss Jim Harris for his encouragement and financial assistance to pursue this graduate degree and the financial assistance involved with the attendance of two conferences in support of this project Finally to the many individuals to assisted in one way another with support encouragement and advice regarding this project including but not limited to Dorothy Reed David Banks Kishor Mehta Franklin Lombardo and Ted Stathopoulos vi TABLE OF CONTENTS Chapte
34. is oriented in the northwest direction The panels were installed parallel to the northwest face of the building and perpendicular to the prevailing wind direction This location and building was chosen due to its similarity to other buildings which have been modeled in previous wind tunnel studies These similarities include the buildings flat roof and parapet the large open field located northwest of the building in the prevailing wind direction and the lack of roof top obstructions in the vicinity of the panels which could 22 influence the behavior of the wind flow Figure3 2 shows a panoramic view of the panel placement on the roof and the general site features which were favorable for comparison with wind tunnel studies The location of the solar panels is indicated by the circle Figure 3 3 is an elevation view of the solar panel installation on the roof with the athletic fields visible in the background Figure 3 2 Location of the Solar Panels on the Event Center Building 23 Figure 3 3 Location of the Solar Panels on the Event Center Building 3 2 Wind Load The Auraria campus is located in downtown Denver Colorado The site elevation is approximately 5200 feet A special wind region exists in Colorado the easternmost boundary of which is approximately defined by Interstate 25 The Auraria Campus shown in Figure 3 4 below is located just east of this boundary 24 k MENU NARRA EA AAA REE 001000502 Sp
35. it and press lt return gt the arrow button or double click on the sensor 4 Previous Next gt Finish Help Le a 9 20 AM me O 03 Figure B 4 Available Sensors and Devices Menu in Short Cut 6 To add strain gages expand the sensors tab in the Available Sensors and Devices Window for the CR5000 Next double click on the Geotechnical and Structural tab and then select Strain Gage Foil Bonded Several options are available In this case 3 wire 350 ohm quarter bridge strain gages were used and wired into the 4WFBS350 TIM modules To add the strain gages to the program select the appropriate gage from the drop down menu of available options and then press the right arrow button to the right of the Available Sensors and Devices window 106 Short Cut CR5000 C Campbelisci SCWin untitled scw Scan Interval 1 0000 Seconds 0 o File Program Tools Progress 1 New Open 2 Datalogger 3 Sensors 4 Outputs 5 Finish Wiring Wiring Diagram Wiring Text Help Available Sensors and Devices Ey crs000 4 y Sensors J Generic Measurements 4 y Geotechnical amp Structural 44 Strain Gage Foil Bonded Omega 000 Q Full Bridge Strain 120 ohm Q Full Bridge Strain 350 ohm Q Half Bridge Strain 1000 ohm with 4WFBS TIM Half Bridge Strain 120 ohm with 4WFBS TIM L Half Bridge Strain 350 ohm with 4WFBS TIM L Quarter Bridge Strain 3 wire 1000 ohm with 4WFB
36. recognize the sociological benefits of solar power Advances in technology have made solar collectors more affordable to homeowners and businesses In the United States a federal residential tax credit of up to 30 is currently available to homeowners who install solar panels to provide electricity for their homes The initial investment is significant however the long term financial savings in electric bills makes up for the upfront costs in some cases homeowners actually receive a check in the mail from the electric company for adding power back to the grid This has led to an increase in the installation of solar panels on many types of structures including residences and commercial buildings Manufacturers of the solar panels have conducted wind tunnel tests to determine the appropriate design wind pressures on the solar panels and the frames to which they are connected Numerous wind tunnel studies have been conducted on solar panels installed on flat roofs however this information is proprietary in nature and not available to the design engineer In an application where solar panels are installed on the roof of an existing building the design wind pressure must be calculated and accounted for to determine the loads imposed on the roof structure The structural design professional is left to use his her judgment to determine the correct procedures to develop wind pressures applied to these roof mounted solar panels Oftentimes the methods e
37. there is an icon at the upper left corner of the screen with a computer keyboard and a plus sign surrounded by a green circle as highlighted in the red box in Figure B 23 below Click on this icon to connect with the data logger a 7 7 RTDAQ 1 1 Datalogger Support Software CR5000 CR5000 folle ls File Datalogger Tools Help DOD CRA 000 O BBF Connect Be Program Monitor Data I Collect Data Datalogger Information Clocks Datalogger Name CR5000 Datal Datalogger Type CR5000 atalogger P PC Direct Connect Connection COM Port COM6 Pause Clock Update Datalogger Settings Baud Rate 115200 Extra Response Time Os Max Time Online 0h Om Os set Clock Datalogger Time Zone Offset O hours O m Datalogger Program Current Program 5 gages 20130601 CR5 Disconnected Figure B 23 Connecting to the Data Logger 31 Once you select the icon above the EZSetup Wizard will open as shown below in Figure B 24 Press next to begin using the wizard 126 y EZSetup Wizard CR5000 CR5000 Progress Introduction Introduction The EZSetup wizard will guide you through the process of setting up your datalogger Follow the instructions given and use the Previous and Next buttons below to navigate through the wizard Communication Setup Datalogger Settings Setup S i i etup Summary Click Next to continue Communication Test Datalogger Clock Send Program Wizard
38. untitled sew Scan Interval 1 0000 Seconds Bg File Program Tools Help Progress 1 New Open 2 Datalogger Properties Wiring 3 Sensors 4 Outputs 5 Finish Temperature Temp_F Available Sensors and Devices Selected O Type T copper constantan Thermocouple Version 3 2 How many Type T TC sensors Max 12 1 Reference Temperature Measurement deg C PTemp_C Wiring Temperature range deg C if reference temperature is 20 deg C 270 to 398 E Advanced Options Wiring Diagram Wiring Text jon Reject 50 Hz Noise 20 ms 500 o Measure second time with reversed inputs to cancel offsets Check for open input A Type T copper constantan Thermocouple Units for Temperature Deg C Deg F K A wiring panel temperature reference in degrees C is required for this sensor Therefore a wiring panel temperature sensor must be selected and configured for degrees C before selecting and configuring this sensor Advanced Options are only available for CRBasic dataloggers Depending on your application you may want to override the default settings shown in the Advanced Options section of this sensor form by enabling Advanced Options and then choosing the settings you desire Figure B 15 Thermocouple Properties Menu 21 Once all of the desired devices have been added to the program press the Next button at the lower right hand corner of the scre
39. vr1000 4 QB Strain 3W 350 Strain 5 Sample Strain 5 microstrain r 4 5 QB Strain 3W 350 5 of 7 Strain 5 QB Strain 3W 350 Strain 6 Sample Strain 6 microstrain vr1000 5 QB Strain 3W 350 Strain 7 Sample Strain 7 microstrain 4 6 QB Strain 3W 350 6 of 7 Strain 6 03001 WS_mph Sample WS_mph miles hour Vr1000 6 03001 WindDir Sample WindDir degrees 4 7 QB Strain 3W 350 7 of 7 Strain 7 03101 WS_mph_2 Sample WS_mph_2 miles hour Vr1000 7 Type T TC Temp_F Sample Temp_F 4 03001 WS_mph WindDir 03101 WS_mph_2 1 Table1 2 Table2 E Advanced Outputs all tables Add Table Delete Table Edit next ai ab 5 21 2013 101PM Figure B 19 Selection the Appropriate interval for PCCard storage 26 Once all the desired sensors have been added and the Outputs have been adjusted your program is complete Adjustments to the program can be made in CRBasic Editor To view and print the Wiring Diagram Click on Wiring Diagram on the left hand side of the screen next to the Selected Sensors window 122 9 Short Cut CR5000 CACampbellscSCWimuntiledscw ScanInterval 1 0000 Seconds II i ha a Sei File Program Tools Help Selected Sensors Selected Outputs eee Sensor Measurement Average ll Table Name Table1 Default panw Minimum ae 3 Sensors f PTemp_C SS v PCCard 4 1 QB Strain 3W 350 1 of 7 Strain 1 p V SC115 CS 1 0 to USB Flash Memory Drive vr1000
40. with Corresponding Cf eee 83 A l Campbell Scientific CR5000 Data Logger ooooccoococcnccccnoncnononcnononcconnnaconancncnncnonnnonos 98 B 1 Procedure for Accessing Short Cut within RTDAQ Program s es 103 B 2 Creating a New Program in Short Cut ooooconnnococnoncccnoncnononcnononanonnnanononcnononcnnnnnncnnnnos 104 B 3 Selecting the Data Logger Model and Scan Interval in Short Cut ee 105 B 4 Available Sensors and Devices Menu in Short Cut 0 0 cece ceeeeeesceesneceeeeeeeeeenees 106 B 5 Adding a Strain Gage in Short Cl ts 107 B 6 Strain Gage Properties WIND Wisin cias 108 B 7 Setting the Gage Factor in the Properties Menu oooconcccnnncnnonononononnnonnnononcnoncnancnnnnno 109 B 8 Adding Anemometers and Weather Vanes oooooonnocccconcccnoncnononcnononanononcconancnonnacinnnos 110 B 9 Properties Menu for the Wind Speed and Direction Sensor ccoocccnnoncccnonccinnnncinnnos 111 B 10 Setting the Units for the Wind Speed Measurements ooococonocccooncccnoncnonancnnnnnncn nnss 112 B 11 Adding additional Anemometer coooccnncccnocnnonncconnnonnnonn nono nonononnncn nan nono nn cnn nnnnrnnnno 113 xvi B 12 B 13 B 14 B 15 B 16 B 17 B 18 B 19 B 20 B 21 B 22 B 23 B 24 B 25 B 26 B 27 Properties Menu for the Anemometers cceeseecesneeceeceeceeeeeceeececeeeeeceneeeenaeers 114 Example Error Message from Short Cut 0 essesceesecceececorecscetsencenseesenteeensees 115 Addi
41. 0 4 of 7 Strain 4 ae L 107 Temperature Probe Wana Text Q 108 Temperature Probe lar Vr1000 4 L 109 Temperature Probe pr 45 QB Strain 3W 350 5 of 7 Strain 5 43347 f vr1000 5 D IRTS P Precision Infrared Temperature Sensor 4 6 QB Strain 3W 350 6 of 7 Strain 6 L SI 111 Precision Infrared Radiometer Q Type E chromel constantan Thermocouple Vr1000 6 L Type J iron constantan Thermocouple E 47 QB Strain 3W 350 7 of 7 Strain 7 ki vr1000 7 L 5 T z tant TI 2 ype Copper constantan Thermocouple 03001 WS_ms Water WindDir Calculations amp Control E 03101 WS_mph a D Devices a a CR5000 Edit Remove A Type T copper constantan Thermocouple a de Units for Temperature Deg C Deg F K A wiring panel temperature reference in degrees C is required for this sensor Therefore a wiring panel temperature sensor must be k selected and configured for degrees C before selecting and configuring this sensor LY fi Advanced Options are only available for CRBasic dataloggers Depending on your application you may want to override the default 5 4 Previous l Next Finish Help 11 44 Am i all 5 26 2013 Figure B 14 Adding a Thermocouple 20 Select the reference temperature units that you would like to record from the drop down menu next to Temperature When the desired units have been selected press OK at the bottom right corner of the screen 116 O Short Cut CR5000 C Campbelisci SCWin
42. 05 le Wind 2 Y E 2 85 in s Z s i NI o a 2 as N E s i j 10 5 Y Cr 5 as I u l Lh La 1 61 121 151 241 301 361 Time seconds Figure 6 10 Time History of Wind Velocity and Strain with Corresponding Cf The time history diagram above is taken from data obtained on 4 14 13 and averaged over a three second interval Cr 12 Table 6 9 Summary of Cr determinations from Figure 6 10 within wind direction tolerance for 3 second rolling averages Cr 3 second Average 9 8 233 1 2 0 7 7 5 22 1 0 0 6 7 2 2 0 1 0 0 5 Te 1 8 1 0 0 4 5 9 1 7 0 9 0 4 4 2 1 6 0 9 0 2 3 7 1 6 0 8 3 2 1 3 0 8 2 8 1 3 0 7 Panel B 3s Strain Interval 3s Average Wind Speed Strain C E F ft gt 2 Strain E Eo 690 v gt 174 2g pa Wind Velocity 3 w o 120 Le tio bras bh d Figure 6 11 Time History of Wind Velocity and Strain with Corresponding Cy The time history diagram above is taken from data obtained on 4 14 13 and averaged over a three second interval 10 l a 18 301 361 Time seconds 74 Table 6 10 Summary of Cr determinations from Figure 6 11 within wind direction tolerance for 3 second rolling averages Cr 3 second Average 11 1 8 0 6 6 6 3 5 2 3 7 3 1 2 6 2 5 X3 2 2 2 1 2 0 2 0 2 0 1 7 1 7 1 4 1 4 1 3 1 2 1 2 1 2 1 1 1 1
43. 0P Wind Directia ae PAZ Vri000 6 7 NRG 40 ds a RM Young Wind Sentry Wind Speed Sensor 6 pi Pp E Units for Wind Speed miles hour meters second Strain 7 L WindSonic4 SDI 12 T kilometers hour knots vr1000 7 A Miscellaneous Sensors en b Temperature WS_ms gt i Water WindDir Calculations amp Control o 4 Previous Next Finish Help 11 35 AM 5 26 2013 Figure B 12 Properties Menu for the Anemometers 17 If the use of three or more anemometers is required the SDMINT8 interval timer will need to be used The anemometers require a pulse port There are only two pulse ports on the data logger When a third anemometer is added to the program in Short Cut the following error message will occur 114 9 Short Cut CR5000 C Campbellsci SCWin untitled scw Scan Interval 1 0000 Seconds x File Program Tools Help Available Sensors and Devices Selected Ani Barometric Pressure a Sensor Measurement a 1 New Open 3 Precipitation roid 5 PTemp_C Gi Relative Humidity amp Temperature 2 Datalogger papel Y d 4 1 QB Strain 3W 350 1 of 7 Strain 1 AREA A Solar Radiation vr1000 1 4 Outputs 4 y Wind Speed amp Direction 4 2 QB Strain 3W 350 2 of 7 Strain 2 5 Finish L 014A Wind Speed Sensor vr1000 2 L 024A Wind Direction Sensor Q 03001 Wind Speed 2 Direction Sensor 4 3 QB Strain 3W 350 3 of 7 Strain 3 Wiring Q 0300
44. 1 SEU Sensor Measurement Processing Output Label Units 4 2 QB Strain 3W 350 2 of 7 Strain 2 iota QB Strain 3W 350 Strain 1 Sample Strain 1 microstrain o Vr1000 2 WindVector QB Strain 3W 350 Strain 2 Sample Strain 2 microstrain Wiring Diagram oS Op Siom IW Sp 3067 S QB Strain 3W 350 Strain 3 Sample Strain 3 microstrain allel chow win diagram sensors to connectors bade QB Strain 3W 350 Strain 4 Sample Strain 4 microstrain ui osa QB Strain 3W 350 Strain 5 Sample Strain 5 microstrain 4 5 QB Strain 3W 350 5 of 7 Strain 5 QB Strain 3W 350 Strain 6 Sample Strain 6 microstrain vr1000 5 QB Strain 3W 350 Strain 7 Sample Strain 7 microstrain 4 6 QB Strain 3W 350 6 of 7 Strain 6 03001 WS_mph Sample WS_mph miles hour Vr1000 6 03001 WindDir Sample WindDir degrees 4 7 QB Strain 3W 350 7 of 7 Strain 7 03101 WS_mph_2 Sample WS_mph_2 miles hour Vr1000 7 Type T Temp_F Sample Temp_F 403001 WS_mph WindDir 03101 WS_mph_2 Type T TC Temp_F Vi Table1 2 Tablez 7 Advanced Outputs all tables Add Table Delete Table Edit Figure B 20 Accessing the Wiring Diagram 27 A wiring diagram will be generated which will give the user specific instructions on where to wire each Sensor 123 8 Short Cut CR5000 CACampbellsciiSCWimuntitled saw ScanInterval 1 0000 Seconds M a a nn ten x File Program Tools Help CR5000 Progress 1 New Open CR5000 Wiring D
45. 1 Temp_F FP2 A EndTable Long 32 bit integer ba Nsec 8 byte time stamp format E DataTable Table2 True 1 DataInterval 0 1440 Min 10 Minimum 1 BattV FP2 False False k EndTable pad o Cali ory table DataT NewFieldCal 10 SampleFieldCal a EndTable gt ABS Main Program ue BeginProg pr z variables for AND ire 350 ohm vith 4WFBS350 TIM measurement Vr1000 AngleDegrees A04 ArrayLength ASCII GFAdj LCount GFsRav LCount ASIN Next ATN Load the most recent calibration values from the CalHist table ATN2 FCLoaded LoadFieldCal True Pera vgRun el t AvaSpa i Line 39 Col 24 C Campbellsci SCWin Example CRS loaded Insert A 2 54 PM 5 27 2013 D pos a i all Figure C 8 Editing the Data Type 7 Prior to leaving the Data Tables section of the program the user must tell the program manually to store the data to the PC card This can be done by using the 137 card out function Under the Data Interval portion of the Define Data Tables section of the program add a space as shown below CRBasic Editor Example CRS for the CRS000 O lle VE a a File Edit View Search Compile Template Instruction Goto Window Tools Help a x EECA TAAT E EEEICT Units Temp F Deg F Define Data Tables DataTable Tablel True 1 Datalnterval 0 1 Sec 10 Sample 1 Strain 1 IEEE4 Sample 1 Strain 2 IEEE4 Sample 1 Strain 3 IEEE4 Sample 1 Strain 4 IEEE
46. 2 Wind Speed 2 Diredf S z Vr1000 3 Wiring Diagram 2 0310 WindiSpeed Senso bin 3W 350 4 of 7 Strain 4 n L 03301 Wind Direction Senflor os D 0344 0348 Wind Speed amp pirectid Short Cut Vr2000 2 O 05103 Wind Speed amp Diredkion Se pin 3W 350 5 of 7 Strain 5 Q 05106 Wind Speed amp Diredtion Se The 03101 Wind Speed Sensor cannot be added because there vr1000 5 i o are not enough free Pulse connections on the CR5000 O 05305 AQ Wind Speed amp irectii ugl bin 3w 350 6 of 7 Strain 6 Q 27106T Wind Speed Sensi Q CS800 Wind Speed amp Direfftion Si Vr1000 6 L NRG 200P Wind DirectiorfiSenso in 3W 350 7 of 7 Strain 7 L NRG 40 Wind Speed Senor n vr1000 7 L WindSonic4 SDI 12 Twof Dimensional Ultrasonic Wind Sensor i WS_ms LA Miscellaneous Sensors 3 Temperature WindDir Water Pr 03101 WS_mph Calculations amp Control Units for Wind Speed miles hour meters second kilometers hour knots RM Young Wind Sentry Wind Speed Sensor 4 Previous Next gt Finish Help 11 39 AM a TD 5 26 2013 Figure B 13 Example Error Message from Short Cut 18 The SDMINTS8 interval timer is not a device that has been preprogrammed into the Available Sensors and Devices menu It will have to be added in the CRBasic Editor As previously mentioned it is better to finish your program in Short Cut prior to opening in CRBasic Editor Once the program has been opened and saved in CRBasic
47. 3s Average Wind Speed Strain C 30 3 Strain E 3 Wind Velocity 8 Wind Velocity mph C 8 N 10 si Ll dea hd llo A 1 61 121 181 241 301 361 Time seconds Figure 6 7 Time History of Wind Velocity and Strain with Corresponding Cr The time history diagram above is taken from data obtained on 4 14 13 and averaged over a three second interval 66 Table 6 6 Summary of Cf determinations from Figure 6 7 within wind direction tolerance for 3 second rolling averages Cr 3 second Average 14 2 2 4 1 0 0 5 5 1 2 3 0 9 0 5 4 9 2 2 0 9 0 5 4 7 1 9 0 9 0 5 4 0 1 8 0 9 0 3 3 7 1 8 0 8 0 3 3 6 1 6 0 8 0 3 3 0 1 6 0 6 0 2 2 8 1 5 0 6 0 2 2 6 1 1 0 6 0 2 2 6 1 1 0 5 2 4 1 0 0 5 5 o ray Strain ue i nm o 120 110 PanelB 3s Strain Interval 3s Average Wind Speed Strain C Strain E Wind Velocity E E ee E 61 181 241 301 361 Time seconds 8 5 8 2 3 Wind Velocity mph C B Figure 6 8 Time History of Wind Velocity and Strain with Corresponding Cr The time history diagram above is taken from data obtained on 4 14 13 and averaged over a three second interval 68 Table 6 7 Summary of Cr determinations from Figure 6 8 within wind direction tolerance for 3 second rolling averages Cr 3 second Average 17 2 1 9 0 9 0 4 7 1 1 8 0 8 0 4 5 0 1 7 0 8 0 4 4 6 1 6 0 8 0 3 4 6 1 5 0 8 0 3 2 9 1 2 0 7 0 3 2 8 1 1 0 6 0
48. 50 ohm with 4WFBS350 TIM measurement Vr1000_2 149 FieldCalStrain 10 Vr1000_20O CReps_2 0 BrZero_2 Mode_2 0 CIndex_2 CAv g 2 0 Strain_2 03001 Wind Speed amp Direction Sensor measurements WS_mph and WindDir PulseCount WS_mph 1 1 1 1 1 677 0 4 If WS_mph lt 0 41 Then WS_mph 0 BrHalf WindDir 1 mV5000 17 3 1 5000 True 0 250 355 0 If WindDir gt 360 Then WindDir 0 03101 Wind Speed Sensor measurement WS_mph_2 PulseCount WS_mph_2 1 2 1 1 1 677 0 4 If WS_mph_2 lt 0 41 Then WS_mph_2 0 Type T copper constantan Thermocouple measurements Temp_F TCDiff Temp_F 1 mV20C 8 TypeT PTemp_C True 0 250 1 8 32 measure 03101 on SDMINTS8 channel 1 through channel 5 SDMINTS8 Int8 0 0002 2222 0002 2222 32768 1 1 677 0 4 For I 1to5 Tf IntS D lt 0 21 Then INT8 D 0 nextIEndProg 150
49. 50 ohm with 4WFBS350 TIM measurement Vr1000 StrainCalc Strain 1 Vr1000 BrZero 1 GFAdj 0 Quarter bridge strain shunt calibration for Quarter Bridge Strain 3 wire 350 ohm with 4WFBS350 TIM measurement Vr1000 FieldCalStrain 13 Strain 1 GFAdj 0 QBSSMode C Known CIndex CAvg GFsRaw 0 Zeroing calibration for Quarter Bridge Strain 3 wire 350 ohm with 4WFBS350 TIM measurement Vr1000 FieldCalStrain 10 Vr1000 CReps 0 BrZero ZMode 0 CIndex CAvg 0 Strain Quarter Bridge Strain 3 wire 350 ohm with 4WFBS350 TIM measurement Vr1000_2 BrFull Vr1000_2 1 mV20 2 1 5 5000 True True 0 250 1 0 Calculated strain result Strain_2 for Quarter Bridge Strain 3 wire 350 ohm with 4WFBS350 TIM measurement Vr1000_2 StrainCalc Strain_2 1 Vr1000_2 BrZero_2 1 GFAdj_2 0 Quarter bridge strain shunt calibration for Quarter Bridge Strain 3 wire 350 ohm with 4WFBS350 TIM measurement Vr1000_2 FieldCalStrain 13 Strain_2 1 GFAdj_2 0 QBSSMode C Known_2 CIndex CAvg GFsR aw_2 0 Zeroing calibration for Quarter Bridge Strain 3 wire 350 ohm with 4WFBS350 TIM measurement Vr1000_2 FieldCalStrain 10 Vr1000_2 CReps 0 BrZero_2 ZMode 0 CIndex CAvg 0 Strain_2 Quarter Bridge Strain 3 wire 350 ohm with 4WFBS350 TIM measurement Vr1000_3 BrFull Vr1000_3 1 mV20 3 1 5 5000 True True 0 250 1 0 Calculated strain result Strain_3 for Quarter Bridge Strain 3 wire 350 ohm with 4WFBS350 TIM measurement Vr1000_2 StrainCalc Strai
50. 8 200 300 Ring A Load vs Strain Calibration Curve y 0 8527x 299 42 R 0 9995 200 100 0 100 200 300 400 500 600 Strain ue Figure 4 5 Calibration Curve for Strain Transducer A 37 Ring B Load ys Strain Calibration Curve y 0 8358x 31 747 0 9879 700 Load Ibs 100 o 100 200 300 400 500 600 Strain ue Figure 4 6 Calibration Curve for Strain Transducer B Ring C Load vs Strain Calibration Curve 700 800 y 0 8722x 291 29 R 0 9978 500 400 T a Dm o s o m 300 200 100 o 100 Strain ue Figure 4 7 Calibration Curve for Strain Transducer C 38 Ring D Load ys Strain Calibration Curve y 0 923 1x 217 26 R 0 9872 450 400 Load Ibs Strain ue Figure 4 8 Calibration Curve for Strain Transducer D Ring E Load vs Strain Calibration Curve 600 y 0 8809x 76 335 R 0 9998 Load Ibs 100 o 100 200 300 400 500 600 700 Strain ue Figure 4 9 Calibration Curve for Strain Transducer E 39 Ring F Load vs Strain Calibration Curve y 0 8922x 41 947 R 0 9735 Load Ibs 0 100 200 300 400 500 600 Strain ue Figure 4 10 Calibration Curve for Strain Transducer F 4 4 3 Strain Transducer Installation One strain transducer was connected to the diagonal tension tie of each leg of the panel The fifth was used to measure change in strain caused by thermal e
51. Adj_5 0 Quarter bridge strain shunt calibration for Quarter Bridge Strain 3 wire 350 ohm with 4WFBS350 TIM measurement Vr1000_5 FieldCalStrain 13 Strain_5 1 GFAdj_5 0 QBSSMode C Known_5 CIndex CAvg GFsR aw_5 0 Zeroing calibration for Quarter Bridge Strain 3 wire 350 ohm with 4WFBS350 TIM measurement Vr1000_5 FieldCalStrain 10 Vr1000_5 CReps 0 BrZero_5 ZMode 0 CIndex CAvg 0 Strain_5 Quarter Bridge Strain 3 wire 350 ohm with 4WFBS350 TIM measurement Vr1000_6 BrFull Vr1000_6 1 mV20 6 2 2 5000 True True 0 250 1 0 Calculated strain result Strain_6 for Quarter Bridge Strain 3 wire 350 ohm with 4WFBS350 TIM measurement Vr1000_6 StrainCalc Strain_6 1 Vr1000_6 BrZero_6 1 GFAdj_6 0 Quarter bridge strain shunt calibration for Quarter Bridge Strain 3 wire 350 ohm with 4WFBS350 TIM measurement Vr1000_6 FieldCalStrain 13 Strain_6 1 GFAdj_6 0 QBSSMode C Known_6 CIndex CAvg GFsR aw_ 6 0 Zeroing calibration for Quarter Bridge Strain 3 wire 350 ohm with 4WFBS350 TIM measurement Vr1000_6 FieldCalStrain 10 Vr1000_6 CReps 0 BrZero_6 ZMode 0 CIndex CAvg 0 Strain_6 Quarter Bridge Strain 3 wire 350 ohm with 4WFBS350 TIM measurement Vr1000_7 143 BrFull Vr1000_7 1 mV20 7 2 2 5000 True True 0 250 1 0 Calculated strain result Strain_7 for Quarter Bridge Strain 3 wire 350 ohm with 4WFBS350 TIM measurement Vr1000_7 StrainCalc Strain_7 1 Vr1000_7 BrZero_7 1 GFAdj_7 0 Quarter brid
52. BS DataInterval 0 1440 Min 10 ACOS Minimum 1 BattV FP2 False False pee EndTable AngleDegrees Calibration history table A04 DataTable CalHist NewFieldCal 10 nese SampleFieldCal ASIN EndTeble ATN ATN2 Main Program rin a Javaspa S Line 34 Col 19 C Campbellsci SCWin Example CR5 loaded Insert Pr i TD Figure C 6 Changing the Desired Output Units in CRBasic Editor 5 The next item in the program is a list of the defined data tables To understand what each of the items in the Define Data Tables section of the program means simply hover over the value and then right click An explanation of each 135 individual value will be provided If the user wishes to change the Sampling interval to store data to the PC card it can be done at this location Note in this case the name of the table which the data will be stored in is called Tablel The data will be stored to the PC card at 1 second intervals CRBasic Editor Example CR5 for the CR5000 er e pS File Edit View Search Compile Template Instruction Goto Window Tools Help elx TEACO ERRATE EREILL Units WS_mph miles hour gt Units minani degrees Units WS mph 2 miles hour Units remp Deg F Define Date Tables DataTable Table1 True 1 O Datalnterval a EA Sample 1 Strain 1 IEEE4 Variables HEndif a Sample 1 Strain 2 IEEE4 Tintolnt b Hi F Sample 1 Strain 3 IEEE4 Beni K
53. S1K TIM o er Bridae a AWEB a Bridge Strain 3 w o ohm with 4WEBS120 TIM DESTE Cone mme Meteorological LA Miscellaneous Sensors 3 Temperature La Water Calculations amp Control Devices CR5000 Parar expected results Selected Sensor Measurement 4 CR5000 4 Default Battv PTemp_C Edit Remove Designed for a strain gage with a nominal resistance of 350 ohms Applies an excitation voltage to a 3 wire quarter bridge strain gage and then performs strain calculations on the measurement The resulting value is the measured voltage in units of microstrain A gage factor can be entered to adjust the measurement result to match 4 Previous Next gt Finish Help Figure B 5 Adding a Strain Gage in Short Cut 7 Once the right arrow is pressed the properties window will automatically open for the strain gages A total of five 350 ohm strain gages can be wired into one excitation voltage In the fourth entry box enter the number of Sensors per Excitation Channel up to a maximum of five Then enter the total number of strain gages that will be used in the first selection window For the purposes of this thesis total strain gages were used Enter the number seven in the first box Note the number of Sensors per Excitation Channel must be entered prior to entering the number of strain gages Otherwise the program assumes that there will be one strain gage wired into ea
54. SSMode CKnown CZ AngleDegrees A04 AnayLength asci ASIN ATN ATN2 Average AvgRun AvaSpa 317PM 5 27 2013 Figure C 11 Editing the Differential Channel 10 To edit the differential channel of each strain gage select and copy the following text within the program 140 Quarter Bridge Strain 3 wire 350 ohm with 4WFBS350 TIM measurement Vr1000 BrFull Vr10000 7 mV20 1 1 5 5000 True True 0 250 1 0 Calculated strain result Strain for Quarter Bridge Strain 3 wire 350 ohm with 4WFBS350 TIM measurement Vr1000 StrainCalc Strain 7 Vr10000 BrZero 1 GFAdj 0 Quarter bridge strain shunt calibration for Quarter Bridge Strain 3 wire 350 ohm with 4WFBS350 TIM measurement Vr1000 FieldCalStrain 13 Strain 1 GFAdj 0 QBSSMode CKnown CIndex CAvg GFsRaw 0 Zeroing calibration for Quarter Bridge Strain 3 wire 350 ohm with 4WFBS350 TIM measurement Vr1000 FieldCalStrain 10 Vr1000 CReps 0 BrZero ZMode 0 CIndex CAvg 0 Strain 11 In the Main Program portion create a new space after the FieldCalStrain 10 VR10000 portion of the program and then paste the information you copied six additional times for a total of seven strain gages The program will then need to be edited as follows so that the differential channel for each strain gage can be adjusted individually The items which must be changed are in bold text below Initialize calibration var
55. STUDY OF WIND LOADS APPLIED TO ROOFTOP SOLAR PANELS by JENNIFER DAVIS HARRIS B S University of Colorado Denver 2006 A thesis submitted to the Faculty of the Graduate School of the University of Colorado in partial fulfillment of the requirements for the degree of Master of Science Civil Engineering 2013 This thesis for the Master of Science degree by Jennifer Davis Harris has been approved for the Civil Engineering Program by Frederick R Rutz Chair Kevin L Rens Yail Jimmy Kim July 12 2013 11 Jennifer Davis Harris M S Civil Engineering Study of Wind Loads Applied to Rooftop Solar Panels Thesis directed by Assistant Professor Frederick R Rutz ABSTRACT The results from a full scale faux solar panel installation research project for two panels placed near the edge of a building with a flat roof on the University of Colorado Denver campus are presented The building and campus are located in downtown Denver CO adjacent to a special wind region A faux solar panel test frame was developed to measure the forces imposed on a full scale solar panel mounted on a flat roof The measured wind direction velocity and corresponding barometric pressure are used to determine the resultant force due to the velocity pressure on the face of the panel The resultant force is derived from the force measured from strain gages connected to a diagonal tension tie on the test frame The force coefficient Cr is determined from t
56. V Units S_mph miles hour Units WindDir degrees Units S_mph_2 miles hour Units Temp F Deg F Define Data Tables DataTable Table2 True 1 DataInterval 0 1440 Min 10 lal Line 23 Col 42 C Campbellsci SCWin Example CRS loaded Figure C 5 Adjusting the Strain Gage Factor in CRBasic Editor 134 4 After the declared variables is a list of the Units for each Sensor The units can be adjusted here if necessary For example if the user decides to measure the temperature in Celsius rather than Fahrenheit go to Units Temp_F Deg C and change to Units Temp_F Deg F If you wish to change the value to Units Temp_C DegC you must also change the Variable name above to Temp_C rather than Temp_F CRBasic Editor Example CRS for the CR5000 W lnc tin lt File Edit View Search Compile Template Instruction Goto Window Tools Help elx ATECA EEE AE Public QBSSMode Public Ciadas Public CAvg Puntie Lcot Public Strain 7 Public Vr1000 7 z Public GFAdj 7 Gee a Public BrZero 7 re Public CKnovn 7 peka L Hut gt amp de 20S 2 105 2 2 2 f Units BattV Volts Units Plemp_C Deg C ba Units Strain microstrain Units Vri000 mv v Units GFAdj unitless Units BrZero mv V ps Units WS _mph miles hour bs Units WindDir degrees Units WS mph 2 miles hour Units Temp _F Deg C E g gt afina Data Tables Bd DataTable Table2 True 1 A
57. al distribution of load as referred to in ASCE7 10 for solar panels mounted on flat roofed buildings was five times the distance of 0 4h The committee determined that the value of a that is appropriate for the design of solar panels on flat roofed building structures is twice the building height The committee explains that the difference is due to the roof and the solar panels being vulnerable to different phenomena The roof is mainly vulnerable to the difference between the pressure within the building and that above the roof Solar panels mounted on the roof are vulnerable to the speed of the wind approaching the panel Because the typical tilt angle of solar collectors mounted on roofs is between 15 to 35 the panels are particularly vulnerable to the vertical uplift component of the wind As mentioned earlier when the wind impacts the windward edge of the building a separation point is developed and a recirculation region lies beneath This increased uplift force on the roof decreases as it gets further away from the edge of the building This phenomenon does not vary with wind speeds and thus the edge zone lengths have been adjusted accordingly to account for this fact Note that the values of the GCy at zone 0 16 are much smaller than at zones 1 3 presumably due to the shielding of these panels by the first line of solar panels in the array as discussed and discovered in previous wind tunnel studies 17 00 oral A F
58. ames was described above in Section 3 4 A schematic diagram of the panel and the resultant forces is illustrated below in Figure 5 3 In Figure 5 3 the pressure distribution is illustrated as a uniformly distributed load acting over the entire surface of the panel In reality the pressure distribution across the panel is not at all uniform However because the resultant force acting on the panel Fr is the desired value the shape of the pressure distribution diagram is irrelevant for the purposes of this research p Icos WIND st R sin0 DIRECTION Ke ccm ROOF Figure 5 3 Schematic Diagram of Forces Acting on the Panel Surface and Frame In this case the strain in the transducers was measured from the force developed in the diagonal tension ties installed on each side of the panel The panels were oriented perpendicular to the wall of the building so that the surface of the panel sloped down 47 toward the roof surface As noted previously a tilt angle 6 equal to 30 degrees was used for both panels A and B The tension tie angle O is equal to 6 degrees for Panel A and 45 degrees for Panel B measured from the horizontal surface of the roof A net resultant wind force imposed on the solar panel Fr will act perpendicular to the surface of the panel From the measured strain in the tension ties the resultant wind force acting on the surface of the solar panel can be calculated by summing the forces in the horizontal di
59. ample 1 Strain 6 IEEE4 ES Sample 1 Strain 7 IEEE4 J f Sample 1 S_mph FP2 E ri Sample 1 WindDir FP2 de Sample 1 WS_mph_2 FP2 Sample 1 Temp_F FP2 y EndTable z DataTable Table2 True 1 DataInterval 0 1440 Min 10 E Minimum 1 BattV FP2 False False lt a EndTable lt gt Calibration history table a DataTable CalHist NewFieldCal 10 a SampleFieldCal gt EndTable ABS ACOS Main Program MAST BeginProg AND Initialize calibration variables for AngleDegrees Quarter Bridge St 3 wire 350 ohm vith 4WFBS350 TIM measurement Vri000 A04 CIndex 1 CAvg 1 CReps 7 Po a For LCount 1 To 7 ASIN GFAdj LCount GFsRaw LCount ATN ieee ATN2 Load the most recent calibration values from the CalHist table Average E AvgRun lal AvaSpa Ss Insert Line 39 Col 8 C Campbellsci SCWin Example CR5 loaded Figure C 10 CardOut Instructions 9 Now that we have told the program to store the data to the PC card scroll down the screen to the Main Program Here you will see a list of all sensors and the nuts and bolts of the program The user can hover over an item in the program for a description of what a certain value is For example scroll down to the portion of the program which says BrFull Vr10000 7 mV20 1 1 5 5000 True True 0 250 1 0 Hover over each item in parenthesis to see what that value represents In this case the cursor was held over the number 1 which is the
60. and Discus Onn LA ene AA eee ee AA 54 6 1 Introduction venvir ii i ee eel ace 54 6 2 Ra o ee 54 RA laine ENE E E a ESES 85 7 Summary Conclusions Possible Sources of Error and Recommendations for Future A a eater ct al ae Peas a etei Great ad tah cuarsba tates aia osi 91 Dale SIA A ae sade ads eh em ean ahead A REEE 91 12 CONCIUSIONS Latin Gaeta el de al a eh aaa aa Ea ia aasa 91 ES Possible Sources OF Prot nce se e SEEN AES Sa 92 7 4 Recommendations tor Future Research eeeeeseeeseeeeesesesesressereresrerseseresreesresseseresee 93 Referentes E a a ts ee 96 1X Appendix A Campbell Scientific CR5000 Data Logger Information oooooconnoccccnoncccnoncninnnanonnnanos 98 B Creating a Program Using Short Cut a dida 102 C Editing a Program Using CRBasic Editor oooococnnococconcccnoncnononcnononnnononcccnnnncnnnnccnnnnos 131 O E I E E E O 146 D Program LIST OF TABLES Table 6 1 Summary of Cr determinations from Figure 6 1 within wind direction tolerance for 3 s cond rolling AVELABES A ai 56 6 2 Summary of Cr determinations from Figure 6 3 within wind direction tolerance for O SECONC LOMING IVETE a nr A 59 6 3 Summary of Cr determinations from Figure 6 4 within wind direction tolerance for S HECONG rolling AVELABES cai 61 6 4 Summary of Cr determinations from Figure 6 5 within wind direction tolerance for Second TONING averages id cie 63 6 5 Summary of Cr determinations from Figure 6 6 within win
61. appropriate interface device e g M C929 9 pin cable or SC324 SC32B Opticall Setup S pin cable or plically a Isolated RS 232 Interface Communication Test Datalogger Clock Send Program Wizard Complete 4 Previous Next gt Cancel Connection Help Figure B 26 Selecting the Data Logger for the Communication Setup 34 The wizard will next ask you to select the appropriate COM Port or computer port which the trend net cable is attached to on your devise Note that the drop down list is not populated in the screen capture below because this list will different for each user Select the appropriate port for your devise 128 EZSetup Wizard CR5000 CR5000 Progress COM Port Selection Introduction COM Port elect the computer s COM Port m here the datalogger is attached Communication Setup Datalogger Settings COM Port Communication Delay If using an SC IRDA device you may need to have a delay before communication is attempted on the COM port This will allow the PC to load the appropriate drivers 2 to 4 seconds should be enough Setup Summary 00 seconds Communication Test Datalogger Clock Send Program Wizard Complete 4 Previous Next gt Cancel COM Port Help Figure B 27 Selecting the COM Port on your computer Follow the remaining instructions through the setup wizard The setup wizard will perform a connection test with the data logger and
62. asses were used to start fire History of Solar 2012 It is documented that in 212 B C Archimedes used the reflective properties of bronze shields to concentrate the suns energy and burn wooden ships from the Roman Empire while attacking the city of Syracuse By the 6 Century A D sunrooms were a common feature in most buildings and the Justinian code initiated sun rights to ensure individual access to the sun History of Solar 2012 Around 1200 A D the Anasazi people built their homes in south facing cliff dwellings in what is now referred to as Mesa Verde In 1767 the first solar collector was developed Horace de Saussure from Switzerland The solar collector perhaps more appropriately labeled a hot box was constructed of five glass boxes stacked inside of one another The outermost box was twelve inches square and six inches high The innermost box was four inches square and two inches high Hot Boxes 2012 In the 1860 s Frenchmen August Mouchet and Abel Pifre developed the first solar powered engine which became the predecessors of modern parabolic dish collectors Next in 1891 the first solar powered water heater was developed in Baltimore by on Clarence Kemp By 1954 photovoltaic technology was born in the United States History of Solar 2012 Daryl Chapin Calvin Fuller and Gerald Pearson of Bell Labs were the scientists credited with developing the first silicon photovoltaic cell which could convert the s
63. asurement and Control System Operator s Manual for detailed user instructions A 2 Instructions The Campbell Scientific CR5000 Data logger is shown below The data logger contains 20 differential channels 4 excitation voltage ports and two pulse ports eisessateceesiizes AAA AAA a em Figure A 1 Campbell Scientific CR5000 Data Logger Figure courtesy of Campbell Scientific Inc Logan Utah 98 Data Logger Calibration At the initial phase of this project the data logger was calibrated by Campbell Scientific The calibration sheet has been located in the UCD Electronic Calibration and Repair Lab Calibration Up to five strain gages can be wired into one excitation voltage port via the 4WFBS350 Terminal Input Modules TIM Short Cut which can be used to create a program used with CR5000 data logger automatically assigns each strain gage to a particular differential channel in the order with which each strain gage or device was added into the program the differential channel assigned by Short Cut can be edited Refer to Appendix B for instructions on generating a program using Short Cut For the purpose of this experiment 350 ohm quarter bridge strain gages were used Three wire leads were soldered to the strain gages and wired to the appropriate differential channel through the 350 ohm TIM If 120 ohm strain gages are used the 120 ohm TIM modules must be used As mentioned preciously both the 350 ohm and the 120 ohm TIM
64. ation Therefore if the change in wind speed was relatively small combined with a relatively large change in strain the magnitude of the Cr value would be large Conversely when the change in wind velocity was relatively large combined with a relatively small change in strain the Cr values would be small It was decided that the values of Cr were relevant when the slope of the curves for the change in strain and the change in wind velocity were in the same direction that is the slope of both curves were positive or both were negative Force coefficients were rejected if a peak in the strain diagram happened to occur where there was little change in velocity over the two second time interval producing an unreasonably large Cr Thus numerous data points were filtered out as irrelevant For example in Tables 6 1 and 6 2 above the overall sampling interval for the data presented was 400 seconds Using the filtering technique only 60 Cr values were retained as relevant The 18 7 and 17 2 Cr values could not be ruled out as invalid It can be seen in Tables 6 1 through 6 8 that force coefficients of 5 10 occur frequently based on a 3 86 second averaging of wind speeds These values are well in excess of the values provided in the SEAOC document The nominal net pressure coefficients obtained from Figure 29 9 1 of that document are a maximum value of 3 6 SEAOC 2012 However this document does not consider solar panels placed within the shear laye
65. ation at the parapet Holmes 2001 The wind flow below this separation layer also called the shear layer is extremely turbulent The wind flow above the shear layer is streamlined The region of turbulent air below the shear layer is called the recirculation region Within the recirculation region there are significant net uplift forces generated near the edge of a building with a flat roof This uplift force dies down or decreases as the distance from the edge of the building increases and the air flow reattaches to the roof ASCE7 10 accounts for this uplift pressure over a distance of 0 4 times the height of the building or 10 percent of the least horizontal dimension of the building whichever is smaller ASCE 7 2010 SHEAR STREAMLINES LAYER eH SEPARATION Se ep POINT gt we N RECIRCULATION REGION Figure 2 1 Principles of Wind Flow against a Bluff Body ASCE 7 uses a probabilistic approach to determine design loading on structures The basic design wind speed values provided in the maps were determined using the three second gust wind speed with a certain percentage of probability of exceedance over 9 a specified time period For example in ASCE7 10 for a risk category II building or other structure the wind speeds provided correspond to a 7 probability of exceedance in 50 years ASCE7 2010 Based on this methodology the value of the wind pressure for solar panels located on the flat ro
66. be developed The panels could also be moved closer to the corner of the building to investigate the effects of dual corner vortices 93 For the purposes of this study sandbags were used to resist the uplift forces on the panels due to wind loads The height of the sandbags particularly for panel A affected the airflow in the recirculation region In the future it would be prudent to use an alternative means of holding down the panels Another suggestion is to adjust the orientation of the panels in order to compare measured strain values and calculated force coefficients determined from wind from various directions The data obtained throughout the course of this study could also be refined for wind from numerous directions It would be desirable to conduct the same tests using real full scale solar panels in place of the test frames developed for use in this study to compare the resulting force coefficients Pressure transducers could be used on the upper and lower surfaces of the panel to measure the differential pressure across it This pressure differential would then be used to generate pressure coefficients Cp for comparison with previous and future wind tunnel studies and also the values provided in the ASCE7 standard The use of accelerometers placed on the upper and lower panel surfaces could be useful to determine the inertial force associated with the vibration of the panel surface The measured strain from the diagonal tensio
67. ccording to this standard the basic wind speed may be reduced by 80 percent for a construction period of six weeks to one year ASCE37 2002 3 3 Design Calculations The design wind pressure as determined above was applied to the surface of the panel The resultant net force acting on the face of the panel was computed Once the resultant force was known the uplift force in the legs of the panel frames and the tension ties was computed It should be noted that the resultant uplift force in the panel legs calculated by this method considers sliding only which is the force acting in the horizontal direction perpendicular to the legs of the panel In this case the vertical uplift force on the panel legs is irrelevant except to determine the weight of the hold downs because the resultant force acting on the face of the panel is calculated using the horizontal component of the force from the diagonal tension tie Throughout the design process of the panel frame consideration was given to both sliding and overturning of the panel and the panel legs were designed for the worst case vertical uplift force and bending moments 26 3 4 Faux Solar Panel Test frame The height of the panels was determined by the location of the shear layer four feet from the outside edge of the parapet It was assumed that the slope of the shear layer slope was 2 1 horizontal to vertical from the leading edge of the parapet SEAOC 2012 The slope of the surface of ea
68. ch of the four excitation voltages This is okay if you are 107 using only four strain gages and no other equipment however if other equipment is required there will need to be open excitation voltages 9 Short Cut CR5000 C Campbelisci SCWin untitled scw File Program Tools Help Available Sensors Ps Ey CR5000 1 New Open 4 7 Sensors 2 Datalogger 3 Generic Me 4 Ly Geotechnic 3 Sensors D Geo Ins 4 Outputs 44 Strain G 5 Finish Q Full Bi 13 Full Q Full B Wiring O Half Wiring Diagram O Half e D Half Wiring Text Q Quar O Quar 13 Quart D VTI EcI 3 Meteorologi LY Miscellane Tempera CA Water 14 Calculations Devices CR5000 Scan Interval 1 0000 Seconds 9 Quarter Bridge Strain 3 wire 350 ohm with 4WFBS350 TIM Version 1 0 2 El Properties Wiring How many QB Strain 3W 350 sensors Max 20 Total Bridge Resistance ohm Excitation Voltage mV Sensors Per Excitation Channel Strain Voltage ratio Range of sensor voltage Measurement integration Settling time microseconds 0 for default Bridge output polarity Gage factor s Select Zeroing Calibration Group 7 8 510 5000 Calculate 5 Calculate microstrain vr1000 20mV y Fast 250 us V V 5 500 o Y Reverse inputs to cancel offsets Y Reverse excitation polarity to cancel offsets inverted from standard conventio
69. ch of the panels was selected to be 30 degrees to maximize the wind effects on the panel The surface of each panel was constructed from 3 8 plywood with dimensions of two feet wide by four feet long The vertical legs of each panel were constructed from 16 gage one inch square tube steel An overview of the construction of panel A is illustrated in Figure 3 5 below CABLE SLIGHTLY SLACK 2x6 pies a HSS1x1x16GAx2 456 N 7 STRAIN TRANSDUCER E ROOF E PAPAPET A HSS1x1x16GAx0 736 PANEL A BELOW SHEAR LAYER 2 1 0 2 a 1 2 1 0 Pa Figure 3 5 Panel A Construction Overview i Y i om 3 PLYWD 6 9 THREADED ROD VARIES 4 0 MAX Because the shear layer develops at a 2 1 horizontal slope with respect the edge of the roof the height of panel A was much shorter than panel B As illustrated in Figure 27 3 6 below the height of panel B is almost twice that of panel A Figure 3 7 is a photograph of panel B as constructed HSS1x1x16GAx5 0 CABLE SLIGHTLY SLACK 36 PLYWD STRAIN TRANSDUCER y 6 2 THREADED ROD 2x6 PAVERS E ROOF E PAPAPET SANDBAG HSS1x1x16GAx3 3 Figure 3 7 Panel B Construction Overview 28 3 5 Connection Details A inch eye bolt was installed through a hole drilled through the top and bottom of the panel legs Tension ties were created from 7 16 inch diameter threade
70. d direction tolerance for 3 second TONING AVELABES RAR 65 6 6 Summary of Cr determinations from Figure 6 7 within wind direction tolerance for SECON TONING APTA Si A E Eas 67 6 7 Summary of Cr determinations from Figure 6 8 within wind direction tolerance for 3 s cond rolling AVELABES A tan 69 xi 6 8 Summary of Cr determinations from Figure 6 9 within wind direction tolerance for 3 sec nd rolling ayerage S ase 71 6 9 Summary of Cr determinations from Figure 6 10 within wind direction tolerance for 3 sec nd TON IM AVET AGES cscs pir r Groce E a a meas 713 6 10 Summary of Cr determinations from Figure 6 11 within wind direction tolerance for 3 sec nd rollins ayera te Si n a E E ed aot a a a oaeeomne TS 6 11 Summary of Cr determinations from Figure 6 12 within wind direction tolerance for SESECOMG TONING AVET ARES sacs in a e E E E egestas T 76 6 12 Summary of Cr determinations from Figure 6 13 within wind direction tolerance for SSECOUG rolling ayerage S n n a e a ea ea gy A A 78 6 13 Summary of Cr determinations from Figure 6 14 within wind direction tolerance for 3 sec nd rollins ayera ge Sr pantune a a E a A ete teas 80 6 14 Summary of Cr determinations from Figure 6 15 within wind direction tolerance for 3J sec nd rolling averages n e a stun gan E A N a 82 6 15 Summary of Cr determinations from Figure 6 16 within wind direction tolerance for S second Tolling Vera Ad A eens sal E aetna Oe 84 xii
71. d height of parapets can also affect the resulting net pressure applied to the face of the panel Figure 2 3 Solar Collector Mounted on a Building with a Flat Roof and a Parapet 13 Many of these items have been studied by solar panel manufacturers but the results of these studies are typically not available in the public domain One study conducted by Sun Link a manufacturer of solar panels determined that the design wind pressures calculated using the methods currently provided in ASCE7 are un conservative It is common for solar panels to be mounted on roof tops in an array An array of solar panels is used rather than individual collectors simply to increase the tributary area of load acting on the panels It is widely known that wind pressure is greater over a smaller area than a larger one The solar panels or arrays of solar panels are attached to an existing roof structure with minimal connections or by a second means of attachment This secondary method of attachment reduces the weight of the system of solar collector panels and support frames so the system can be held down on the roof s structure with ballast sufficient to resist the uplift force during a design wind event Tilley 2012 The study found that the pressures that developed on the roof were well in excess of 15 pounds per square foot psf even in a mild wind event therefore the uplift pressures could be well in excess of this value during a design wind event Very
72. d steel rod which was through bolted to a strain transducer through a Y2 inch diameter hole The tension ties were installed at an angle of 6 degrees for panel A and 45 degrees for panel B The slope of the tension ties was determined once the height of each panel was known Nuts were fastened to each side of the wall of the strain transducer to allow for adjustment and pretensioning of the ties in the field The tension ties were connected to the panel legs by a coupler nut A 5 16 diameter hole was drilled through one end of the 7 16 diameter coupler nut which was threaded onto the tension tie and attached to the Ya eyebolt at the top and bottom of the panel legs as shown in Figure 3 8 It was intended that this connection remain a pin end connection in order to direct all horizontal components of force into the diagonal tension tie where the force could be monitored via the strain transducers The strain transducers were fabricated from three inch diameter by two inch wide steel rings with strain gages adhered to their inside surfaces A cable brace was installed slightly slack in the opposite direction of the tension tie to provide stability for the frame for the case of wind blowing in the opposite direction as illustrated in Figure 3 5 and 3 6 The top of the panel legs were connected to the 3 8 plywood panel surface via 2 diameter bolts through 1x1x1 8 steel angles that were six inches long The same connection was used at the ba
73. e actual surface area of the panel not the projected vertical area The term Cr or force coefficient is used in lieu of pressure coefficient because it is derived from the measured forces acting on the panel rather than the net pressure across the surface of the panel As previously mentioned the resultant force acting on panel is determined from strain measurements generated from the force in the diagonal tension ties The strain transducers were fabricated using a steel ring with a strain gage mounted to the inside face Because the forces developed in the tension ties and the corresponding strain measurements are small the ring transducers were used to mechanically amplify the measured strain If the strain gages were mounted directly to the legs of the legs of the test frame the changes in strain would be so small they would be imperceptible There are several factors which could impact the output of the strain transducers The thermal output of each strain gage is affected by temperature Vishay who manufactured the strain gages used in this study provided a graph and an equation to correct the measured 49 strain from each gage for thermal output The gage factor of the strain gages also varies slightly with temperature To complicate matters further the steel ring to which the strain gages were mounted as well as the legs of the panel and the diagonal tension ties are all subject to thermal expansion and contraction Temperature was measur
74. e of the panel For the purposes of this study a test frame was developed to calculate the net force acting on the face of the panel Therefore instead of pressure coefficients force coefficients Cr were calculated from the measured data The methodology used to calculate the force coefficients is described as follows 5 2 Wind Interaction with the Panel As discussed in Section 2 3 as wind flow impacts a bluff body such as a building several phenomena occur A separation occurs at the roof edge and a region of turbulent air flow develops on the surface of the roof over a certain distance For the purposes of this study it was desired to investigate the force coefficients developed when a solar panel was placed within the shear layer Panel B was designed so that the midpoint of the face of the panel would intersect the shear layer It was assumed that a secondary separation point and shear layer and recirculation region would develop on the panel s face as depicted below in Figure 5 1 Panel A was placed below the shear layer therefore the entire panel was located within the recirculation region as illustrated in Figure 5 2 45 Figure 5 1 Schematic Diagram of Wind Interaction at Panel B Figure 5 2 Schematic Diagram of Wind Interaction with Panel A 46 The wind velocity was measured below the shear layer at the shear layer and well above the shear layer 5 3 Calculations The construction of the faux solar panel test fr
75. e testing it is a necessary component to validating the pressure coefficients determined from wind tunnel studies In an effort to provide data for comparison with past and future wind tunnel studies and numerical analyses full scale testing has been conducted at the University of Colorado Denver 21 3 Panel Design Location and Installation 3 1 Description Initially three faux solar panel test frames were proposed and designed for the purposes of this study Dowds et al 2012 The test frames were designed to emulate a solar panel and measure the forces they were subjected to near the edge windward edge of a flat roof The panels were labeled Panel A Panel B and Panel C Panel A was designed so that the entire panel would be encompassed within the recirculation region below the shear layer Panel B was designed so that the midpoint of the face of the panel would intersect the shear layer Panel C was designed so that the entire panel would be located above the shear layer Once the design process began and the dimensions of the three panels were determined and the uplift forces on each leg of the panel were calculated it was determined that Panel C was unfeasible The height of Panel C would have been unrealistic and therefore 1t was decided to construct only Panels A and B The panels were installed on the roof of the Events Center building at the University of Colorado Denver s Auraria campus as shown in Figure 3 1 below The building
76. ecial Wind Region University of Colorado Denver Colorado PURER ERR EER ERE EER EER EEE EERE EE EER EET EERE ERE ERE EERE EEE EERE EEE EE SE IPE EREEREEREERS ERE ERE ERE ERE ERE AAA ERE EEE TS Figure 3 4 Site Location of the University of Colorado Denver The Auraria Campus home to the University of Colorado Denver is bordered by a special wind region on its western boundary The site campus location is indicated by the star The prevailing wind direction for the site is from the northwest which is approximately broadside to the building The elevation at the roof of the Events Center building on campus is approximately 5 248 feet The height of the building is approximately 38 feet The exposure category is B according to the definitions set forth in ASCE7 10 The design wind load on the solar panel test frames was approximated using section 30 8 2 of ASCE7 10 In absence of guidance from ASCE 7 regarding the design wind loads on solar panels it was assumed that this section closely depicted the interaction between the wind and the panel frame Section 30 8 2 is used for the design 25 of components and cladding wind loads on open buildings with monoslope pitched or troughed roofs ASCE7 2010 The basic wind speed used was 115 mph according to Figure 26 5 1A of ASCE7 10 for Risk Category II Buildings The wind load was reduced by 80 percent according to the provisions for short duration installations in chapter 6 of ASCE 37 A
77. ed amp Di Vr1000 2 Wiring Diagram Q 03101 Wind Speed Sen Strain 3 ES Q 03301 Wind Direction Sel SS Q 034A 0348 Wind Speed Vr1000 3 O 05103 Wind Speed amp Dir Strain 4 Q 05106 Wind Speed amp Dirt vr1000 4 Q 05305 AQ Wind Speed 8 strain 5 Q 27106T Wind Speed Sel Q CS800 Wind Speed amp Di Vr1000 5 O NRG 200P Wind Directia Strain 6 r aches ey a Se vr1000 6 WindSonic4 SDI 12 T LA Miscellaneous Sensors Siren La Temperature RM Young Wind Sentry Wind Speed and Direction wraoont7 La Water Sensor Calculations amp Control Units for Wind Speed meters second i kilometers hour miles hour knots Units for Wind Direction degrees Figure B 10 Setting the Units for the Wind Speed Measurements 15 Once you have entered your desired units press OK at the bottom of the properties menu The weather vane and one anemometer have now been added to the Selected Sensors window on the right hand side of the screen To add one additional anemometer Go back to the available sensors and devices menu and select the 03001 Wind Speed Sensor Press the right arrow button to the right of the Available Sensors and devices window 112 9 Short Cut CR5000 C Campbelisci SCWin untitledsew Scan Interval 1 0000 Seconds a File Program Tools Help Available Sensors and Devices Selected _ progress 1 Barometric Pressure s Sensor Measurement S 1 New Open gt Halen c
78. ed through a thermocouple which was compared to the ambient air temperature reported on the National Climactic Data Center website U S Department of Commerce 2013 However the effect of solar radiation on the various components was unknown Therefore 1f the resultant force measured from the strain transducers was used directly to determine the force coefficient the results would be in error unless the measured strain was corrected for the thermal effects described above A technique was developed to calculate the force coefficient on the panel which was independent of thermal effects Figure 5 4 below is a schematic time history used to illustrate this technique Ne h Nae STRAIN WIND VELOCITY Strain ue Wind Velocity mph At 2 sec Figure 5 4 Schematic Time History Diagram of Wind Velocity and Strain For each gust a plot can made of the wind velocity and corresponding strain measured from the strain transducers over a specified time interval When gusts occur 50 there is a peak in the wind velocity diagram and a corresponding peak in the measured strain This occurs each time the wind strikes the panel from a particular direction over the duration of the gust In this case that wind direction was set to be 180 degrees The force coefficient Cr was calculated by taking the difference between the measured strains over a two second interval and dividing that value by the change in the square of the veloci
79. emp_C FP2 Sample 1 Strain 1 IEEE4 Sample 1 Vr1000 1 TEEE4 Sample 1 Strain 2 IEEE4 Sample 1 Vr1000 2 JEEE4 Sample 1 Strain 3 IEEE4 Sample 1 Vr1000 3 JEEE4 Sample 1 Strain_2 1 JEEE4 Sample 1 Vr1000_2 1 TEEE4 Sample 1 Strain_2 2 JEEE4 Sample 1 Vr1000_2 2 TEEE4 147 Sample 1 Strain_2 3 IEEE4 Sample 1 Vr1000_2 3 IEEF4 Sample 1 Strain_2 4 IEEE4 Sample 1 Vr1000_2 4 IEEF4 Sample 1 WS_mph FP2 Sample 1 WindDir FP2 Sample 1 WS_mph_2 FP2 Sample 1 Temp_F FP2 Sample 1 INT 8 FP2 EndTable DataTable Table2 True 1 Datalnterval 0 1440 Min 10 Minimum 1 BattV FP2 False False EndTable DataTable Dat5min 1 1 DataInterval 0 1 Sec 10 CardOut 0 1 Sample 5 Int8 JIEEE4 EndTable Calibration history table DataTable CalHist NewFieldCal 10 CardOut 0 10 SampleFieldCal EndTable Main Program BeginProg Initialize calibration variables for Quarter Bridge Strain 3 wire 350 ohm with 4WFBS350 TIM measurement Vr10000 CIndex 1 CAvg 1 CReps 3 For LCount 1 To 3 GFAdj LCount GFsRaw LCount Next Initialize calibration variables for Quarter Bridge Strain 3 wire 350 ohm with 4WFBS350 TIM measurement Vr1000_20 CIndex_2 1 CAvg_2 1 CReps_2 4 For LCount_2 1 To 4 GFAdj_2 LCount_2 GFsRaw_2 LCount_2 Next 148 Load the most recent calibration values from the CalHist table FCLoaded LoadFieldCal True Main Scan Scan 1 Sec 1 0 Default Datalogger Battery Volta
80. en 22 The Selected Sensors now appear in the window on the left hand side of the screen In the middle of the screen there are several options such as Average Minimum Maximum Sample StdDev Total and Wind Vector 117 Seia 9 Short Cut CR5000 C File Program Tools Help Selected Sensors Selected Outputs Hada Sensor Measurement Aviirage Table Name Table open 4 CR5000 Mafimum gt 2 Datalogger Dele men Store Every 60 Minutes 3 Sensors PTemp_C E PCCard 4 Outputs 4 1 QB Strain 3W 350 1of7 Strain 1 Sample L F sc115 cs 1 0 to USB Flash Memory Drive 5 Finish Vr1000 1 ue Sensor Measurement Processing Output Label Units 4 2 QB Strain 3W 350 2 of 7 Strain 2 ptal Wiring Vr1000 2 Wwindvector Wiring Diagram 4 3 QB Strain 3W 350 3 of 7 Strain 3 Wiring Text Vr1000 3 4 4 QB Strain 3W 350 4 of 7 Strain 4 vr1000 4 45 QB Strain 3W 350 5 of 7 Strain 5 Vr1000 5 4 6 QB Strain 3W 350 6 of 7 Strain 6 Vr1000 6 47 QB Strain 3W 350 7 of 7 Strain 7 vr1000 7 4 03001 WS_ms WindDir 03101 WS_mph Type T TC Temp_F Va Table1 2 Tablez E Advanced Outputs all tables Add Table Delete Table Edit Remove Finish Help a Pe ll D Figure B 16 Selected Sensors Window 23 Select the desired sensor and then select the type of processing which you would like the program to perform In this case it is desired that all the data be captured and post processed
81. ere investigated in this study The data collected and the calculated force coefficients are offered for comparison to the findings of other researchers In this study peak force coefficients for panels located near the edge of a flat roof were generated from wind directions perpendicular to the face of the panel It was concluded that the net peak pressure coefficient for this panel was 5 7 For the purpose of conducting full scale testing a faux solar panel test frame was created The solar panel test frames developed for this thesis are offered as an alternative means to monitor forces due to wind on rooftop solar panels Design professionals should proceed with caution when calculating the design wind pressures on solar panels placed near the edge of a flat roof If the building and panels were subjected to a design wind event considerable damage could be imposed on the roof structure by the uplift forces generated 7 3 Possible Sources of Error Errors could be introduced from various sources including but not limited to the following The data was recorded at one second intervals While examining the raw data it became apparent that there were many locations where a high gust was recorded but either the minimum or maximum wind velocities were not captured or the maximum strain was not captured If the data collection interval was reduced the strain values closer to the minimum and maximum that occurs concurrently with the maximum rec
82. few roofs if any provide sufficient ballast to resist 15 psf of uplift pressure At the 2012 Structures Congress Dr Ted Stathopoulos of Concordia University Montreal Quebec Canada presented a paper summarizing the various values of pressure coefficients that were measured in four different wind tunnel studies Stathopoulos 2012 The comparison included the results provided in the Radu study published in 1986 and three other studies conducted in 2011 The conclusion of Dr Stathopoulos was that in there was poor agreement between the results of these four wind tunnel studies There 14 was very little correlation between measured values for the pressure coefficient even when the solar collector panels were mounted at the same tilt angle and the wind was blowing from the same direction Stathopoulos 2012 It is clear that despite the numerous studies that have previously been conducted in the wind tunnels more research and validation is necessary to determine design values of the pressure coefficient on flat roof mounted solar panels Recently the Structural Engineers Association of California SEAOC developed a Wind Loads on Solar Collectors Subcommittee SEAOC 2012 The specific purpose of this committee was to develop design procedures for wind loading applied to solar collectors arrays on flat roof low rise buildings in the interim period until these design procedures are published in the ASCE 7 standard As there may be
83. ffects only The sixth strain transducer served as a backup if there was a malfunction with one of the other five transducers The strain transducers were covered with foil insulation to guard against solar radiation heating them above the ambient air temperature Strain transducers A and B were connected to panel A strain transducers B and E were connected to panel B and strain transducer F was not connected to a panel but used to measure change in strain due to thermal effects Figure 4 11 below shows the solar panel layout the strain transducers are labeled below the corresponding panel leg they were connected to 40 E A Rs STRAIN D STRAIN_2 1 PANEL B E A STRAIN E STRAIN 3 STRAIN F STRAIN_2 2 FOR TEMPERATURE MEASUREMENTS E A STRAIN A STRAIN 1 PANEL A E Qu STRAIN B STRAIN 2 Figure 4 11 Strain Transducer Instrumentation Plan 4 5 Anemometers Three RM Young 3101 Wind Sentry Anemometers were used to record the wind speed Wind speed is measured with a three cup anemometer Rotation of the cup when produces an ac sine wave voltage with frequency proportional to wind speed Campbell Scientific 2007 The anemometers are shown in Figure 4 12 below 41 Cable Tie Crossarm 1049 NU RAIL Fitting Figure 4 12 RM Young 3101 Anemometer Courtesy of Campbell Scientific Inc Logan Utah 4 6 Wind Direc
84. fourth value in the parenthesis This value represents the differential channel that the program is expecting the first strain gage to be wired into If it is desired to change the differential channel it can be done here The program is currently telling the data logger that there are 7 strain 139 gages named Vr1000 which will be wired into differential channels 1 7 The number 1 which is the fifth item in the parenthesis corresponds to the excitation channel and the number 5 which is 6 in the list corresponds to the number of gages per excitation channel What this portion of the program is telling the data logger is that the first 5 strain gages will be wired into differential channels 1 5 which will all be wired into excitation voltage 1 VX1 on the data logger the next two strain gages will be wired into differential channels 6 7 which will be wired into excitation voltage 2 VX2 If it is desired to change the differential channel of a particular strain gage the program must be edited CRBasic Editor Example CRS for the CRS000 nnn in File Edit View Search Compile Template Instruction Goto Window Tools Help e ATA EPA AAA m 1 For LCount 1 To 7 Adj LCount GFsRaw LCount urement Plemp C fs with WFBS350 TIM measurement Vr1000 vith 4WFBS350 TIM measurement Vr1000 ibration for re 350 ohm vith 4WFBS350 TIM me 1 GFAdj 0 QB
85. further illustrate how the Cp values were filtered Panel B 4 14 13 90 250 200 F 30 Wind Direction degrees 1 61 121 181 241 301 361 Time seconds Figure 6 2 Results of Wind Direction Plotted Versus Cy from April 14 2013 Cr values for all wind directions are shown here The 400 second time history and Cr values computed from 9 second rolling averages are shown below in Figure 6 3 and Table 6 2 for a wind direction perpendicular to the panel Note that Figure 6 3 was created from the same data over the same time 57 interval as depicted in Figure 6 1lusing a 9 second rolling average in an attempt to reduce the variation in the curve and the variation in the force coefficients Panel B 4 14 13 9s Strain Interval 9s Average Wind Speed a STRAIN E 145 A gt NA PRA ee O 45 II ARA A IR 40 125 T STRAIN C 35 be o mn e VELOCITY co ua Strain ue Wind Velocity mph 1 61 121 181 241 301 361 Time seconds Figure 6 3 Wind Velocity Strain and calculated Cr Values from 4 14 13 Data C The values were taken from a selected record averaged using a 9 second rolling average 58 Table 6 2 Summary of Cr determinations from Figure 6 3 within wind direction tolerance for 9 second rolling averages Cr 9 second Average 13 8 11 5 7 1 6 5 4 0 3 6 22 2 2 2 0 2 0 1 9 1 8 1 8 1 7 1 7 1 7 1 6 1 5 1 5 1
86. ge measurement BattV Battery BattV Default Wiring Panel Temperature measurement PTemp_C PanelTemp PTemp_C 250 Quarter Bridge Strain 3 wire 350 ohm with 4WFBS350 TIM measurement Vr10000 BrFull Vr1000 3 mV20 1 1 3 5000 True True 0 250 1 0 Calculated strain result Strain for Quarter Bridge Strain 3 wire 350 ohm with 4WFBS350 TIM measurement Vr1000 0 StrainCalc Strain 3 Vr10000 BrZero 1 GFAdj 0 Quarter bridge strain shunt calibration for Quarter Bridge Strain 3 wire 350 ohm with 4WFBS350 TIM measurement Vr1000 0 FieldCalStrain 13 Strain 1 GFAdj 0 QBSSMode CKnown CIndex CAvg GF sRaw 0 Zeroing calibration for Quarter Bridge Strain 3 wire 350 ohm with 4WFBS350 TIM measurement Vr1000 FieldCalStrain 10 Vr1000 CReps 0 BrZero ZMode 0 CIndex CAvg 0 Strain Quarter Bridge Strain 3 wire 350 ohm with 4WFBS350 TIM measurement Vr1000_2 BrFull Vr1000_2 4 mV 20 4 2 4 5000 True True 0 250 1 0 Calculated strain result Strain_2 for Quarter Bridge Strain 3 wire 350 ohm with 4WFBS350 TIM measurement Vr1000_2 StrainCalc Strain_2 4 Vr1000_2 BrZero_2 1 GFAdj_2 0 Quarter bridge strain shunt calibration for Quarter Bridge Strain 3 wire 350 ohm with 4WFBS350 TIM measurement Vr1000_2 FieldCalStrain 13 Strain_2 1 GFAdj_2 0 0 QBSSMode_2 CKnown_2 CIndex_ 2 CAvg_2 GFsRaw_2 0 Zeroing calibration for Quarter Bridge Strain 3 wire 3
87. ge strain shunt calibration for Quarter Bridge Strain 3 wire 350 ohm with 4WFBS350 TIM measurement Vr1000_7 FieldCalStrain 13 Strain_7 1 GFAdj_7 0 QBSSMode CKnown_7 CIndex CAvg GFsR aw_7 0 Zeroing calibration for Quarter Bridge Strain 3 wire 350 ohm with 4WFBS350 TIM measurement Vr1000_7 FieldCalStrain 10 Vr1000_7 CReps 0 BrZero_7 ZMode 0 CIndex CAvg 0 Strain_7 12 Once the Main Program has been edited you must return to the Declare Variables and Units of the program and declare the variable names and the units for each of the seven strain gages The variables and units will read as follows Public Strain Public Vr1000 Public GFRaw Public GFAdj Public BrZero Public CKnown Public CReps Public ZMode Public QBSSMode Public CIndex Public CAvg Public Strain_2 Public Vr1000_2 Public GFRaw_2 Public GFAdj_2 Public BrZero_2 Public CKnown_2 Public CReps_2 Public ZMode_2 Public QBSSMode_2 Public CIndex_2 Public CAvg_2 144 13 To add the SDM INTS Interval timer to the data logger see the User s Manual for the Interval Timer There is a sample program within the manual along with detailed instructions on how to write the interval timer into your program The final program used in this study has been provided in Appendix D The following program instructions were used for the purpose of this study measure 03101 on SDMINTS8 channel 1 through channel 5 SDMINT8 Int8 0 0002 2222 0002 2222 32768 1 1 677 0 4
88. ger and computer and press the connect button as highlighted above 130 C Editing a Program Using CRBasic Editor C 1 Introduction A brief instruction on working with CRBasic Editor to edit a program created using Short Cut is provided below C 2 Instructions 1 To edit a program once it has been created in Short Cut open the RTDAQ program and open the CRBasic Editor CRBasic Editor is the round blue icon with a white pencil shown in Figure C 1 below Or go to the Tools menu and select CRBasic Editor as shown in Figure C 2 below 7 RTDAQ 1 1 Datalogger Support Software CR5000 c Datalogger Network Tools Help wml 3 O ARRABA Clock Program Monitor Data Collect Data st a Datalogger Information Clocks CR5000 Datalogger Name CR5000 Datalogger Type CR5000 Datalogger 2 PC Direct Connect Connection COM Port COME gt E Pause Clock Update Datalogger Settings Baud Rate 115200 A Extra Response Time Os Datalogger Time Zone Offset Max Time Online Oh Om Os Senet D hours Om Datalogger Program Current Program WindSolarFinal_20130337 CR5 Send Program Disconnected 206PM 5 21 2013 E aul Figure C 1 Accessing CRBasic Editor in the RTDAQ Program 131 a 0o00 o0 Clock RTMC Development RTMC Run time Dal ViewPro Clocks Pi Split Datalogger Card Co
89. h was created using the Short Cut software provided with the data logger In Appendix C a summary of instructions is provided in order to edit a program which was created using the Short Cut software The program used for the purposes of this study has been provided in Appendix 2 History of Solar Energy 2 1 Introduction The use of solar collectors as an alternative means of energy production is becoming a viable alternative among many energy conscious businesses and homeowners The since the 1950 s when the silicon photovoltaic PV cells were developed efforts have been focused on increasing the efficiency of PV systems and reducing their costs With the decrease in cost there has been an increase in solar collector installations Design professionals have little guidance for determining design wind pressures acting on the solar panels There is little agreement between the force coefficients determined from previous wind tunnel studies Full scale testing is necessary to validate the results from these previous wind tunnel studies The following chapter is a literature review offering a brief summary of the history of solar energy the basic principles of bluff body aerodynamics and an overview of the results of some previous wind tunnel studies 2 2 History of Solar Energy According to the U S Department of Energy the earliest documented uses of concentrating the sun s energy date back to the ras Century B C when magnifying gl
90. h_2 Type T TC Temp_F Na Table1_ 2 Table2 E Advanced Outputs all tables Add Table Delete Table Edit Figure B 17 Selecting the Outputs for each Sensor 24 This process must be repeated for each individual Sensor 119 9 Short Cut CR5000 C Campbellsci SCWin untitledsew Scan Interval 1 0000 Seconds M GT x File Program Tools Help Selected Sensors Selected Outputs Progress Sensor Measurement Average Table Name frablez 1 New Open 4 CR5000 2 Datalogger Store Every fa Seconds y g 4 Default Battv 3 Sensors PTemp_C E PCCard gt 4 Outputs 2 1 QB Strain 3W 350 1of7 Strain 1 E sc115 CS 1 0 to USB Flash Mi 5 Hadi Vr1000 1 Sensor Measurema nt Processing Output Label Units 4 2 QB Strain 3W 350 2 of 7 Strain 2 Total QB Strain 3W 350 Strain 1 Sample Strain 1 microstrain LY Vr1000 2 WindVector QB strain 3W 350 Strain 2 Sample Strain 2 microstrain Weng Degen A Senn Strain 3 QB Strain 3W 350 Strain 3 Sample Strain 3 microstrain Wiring Text Vr1000 3 7 in 4 QB Strain 3W 350 Strain 4 Sample Strain 4 microstrain 4 4 QB Strain 3W 350 4 of 7 Strain 4 Vv oo QB Strain 3W 350 Strain 5 Sample Strain 5 microstrain r 4 5 QB Strain 3W 350 5 of 7 Strain 5 QB Strain 3W 350 Strain 6 Sample Strain 6 microstrain vr1000 5 QB Strain 3W 350 Strain 7 Sample Strain 7 microstrain 4 6 QB Strain 3W 350 6 of 7 Strain 6 03001 WS_mph Samp
91. hat force coefficients were calculated when the wind was blowing from the direction of interest A tolerance of 10 degrees was allowed Therefore Cr values were calculated when the wind direction was 170 degrees to 190 degrees as illustrated in Figure 5 5 below Panel B 4 14 13 300 100 A Hh Mi AM 15 aN A PAN co l 10 di a A L 10 Taa bap AA Wind Direction el G o p o o Time seconds Figure 5 5 Filtered Wind Direction for Cr Calculation To validate the initial assumption regarding the maximum force coefficients two additional wind directions were also investigated The additional wind directions considered were 20 degrees and 45 degrees from the axis perpendicular to the panel A 10 degree tolerance was also allowed 52 53 6 Results and Discussion 6 1 Introduction For purposes of this thesis the findings from panel B the panel located within the shear layer are reported upon The results from panel A were inconclusive The wind velocity direction and strain were collected using a sampling interval of one second Data was post processed over three second rolling averages 6 2 Results The results from the data analysis from the wind direction perpendicular to the face of the panel corresponding to 180 are presented in the time histories below in Figures 6 1 and Figures 6 3 through 6 9 A summary of the force coefficients Cr calculated for the selected 400 second time history plotted in
92. he ratio of the resultant panel force determined from strain measurements and the force determined from the velocity pressure Cr values so determined are presented within The form and content of this abstract are approved I recommend its publication Approved Frederick R Rutz 111 DEDICATION I dedicate this work to my parents Richard and Susan Davis and my husband Michael Harris who have patiently waited for me to complete this journey iv ACKNOWLEDGMENTS In an effort to express the sincerest form of gratitude to the multitude of individuals who assisted with this project the author wishes to acknowledge the following individuals Dr Frederick R Rutz my advisor who has been instrumental in the organization and implementation of this project Your wisdom encouragement and support have not gone unnoticed Without your assistance both physically and intellectually this project would not be where it is today To my co researcher and fellow graduate student Erin Dowds who has graciously allowed me to participate in this research project this was your brainchild and although I have finished first credit is due to you I will be there to help you continue this research and I am sincerely grateful for all of your help designing building and carrying sand bags and faux solar panels on the roof of the PE building Sincere thanks is offered to Drs Kevin Rens and Jimmy Kim of the Civil Engineering Department at UCD not only for
93. hey are mounted and the connections between the frame and the roof structure When solar panels are mounted on the roofs of existing structures the roof system must be checked to determine if it is capable of resisting the uplift force applied to it by the solar panels Engineering standards typically used by design professionals such as ASCE7 ASCE7 2010 make no mention as to what type of wind loads should be applied to roof mounted solar panels Because of this the design professional is left to use his or her judgment to formulate an appropriate methodology to determine design wind pressures on solar panels and their effects on the roof structure 1 2 Goal The goal of this research is to determine the force coefficients acting on the face of solar collectors mounted near the edge of a flat roof structure in order to calculate the appropriate wind pressure for design Itis expected that the peak force coefficients determined from this study will be well in excess of the pressure coefficients used in the ASCE7 standard However the ASCE7 standard does not address the design of solar panels The results are offered for comparison with previous wind tunnel studies The proposed research was presented at the 3rd American Association of Wind Engineers Workshop in Hyannis MA Aug 12 14 2012 Dowds et al 2012 In order to accomplish this goal two faux solar panel test frames were developed to measure the resultant forces acting on the face
94. iables for Quarter Bridge Strain 3 wire 350 ohm with 4WFBS350 TIM measurement Vr1000 CIndex 1 CAvg 1 CReps 1 GFRaw 2 GFAdj GFRaw Initialize calibration variables for Quarter Bridge Strain 3 wire 350 ohm with 4WFBS350 TIM measurement Vr1000_2 CIndex_2 1 CAvg_2 1 CReps_2 1 GFRaw_2 2 GFAdj_2 GFRaw_2 141 Initialize calibration variables for Quarter Bridge Strain 3 wire 350 ohm with 4WFBS350 TIM measurement Vr1000_3 CIndex_3 1 CAvg_3 1 CReps_3 1 GFRaw_3 2 GFAdj_3 GFRaw_3 Initialize calibration variables for Quarter Bridge Strain 3 wire 350 ohm with 4WFBS350 TIM measurement Vr1000_4 CIndex_4 1 CAvg_4 1 CReps_4 1 GFRaw_4 2 GFAdj_4 GFRaw_4 Initialize calibration variables for Quarter Bridge Strain 3 wire 350 ohm with 4WFBS350 TIM measurement Vr1000_5 CIndex_5 1 CAvg_5 1 CReps_5 1 GFRaw_5 2 GFAdj_5 GFRaw_5 Initialize calibration variables for Quarter Bridge Strain 3 wire 350 ohm with 4WFBS350 TIM measurement Vr1000_6 CIndex_6 1 CAvg_6 1 CReps_6 1 GFRaw_6 2 GFAdj_6 GFRaw_6 Initialize calibration variables for Quarter Bridge Strain 3 wire 350 ohm with 4WFBS350 TIM measurement Vr1000_7 CIndex_7 1 CAvg_7 1 CReps_7 1 GFRaw_7 2 GFAdj_7 GFRaw_7 Quarter Bridge Strain 3 wire 350 ohm with 4WFBS350 TIM measurement Vr1000 BrFull Vr1000 1 mV 20 1 1 5 5000 True True 0 250 1 0 Calculated strain result Strain for Quarter Bridge Strain 3 wire 3
95. iagram for untitled scw Wiring details can be found in the help file a 2 Datalogger oa QB Strain 3W 350 1 Strain 1 Vr1000 1 CR5000 4 Outputs AWFBS350 1 q 5 Finish A Common H A Common L Wiring E aN Dine H pin 1H Wiring Diagram g a Lpin iL Wiring Text Gpin ct Ground Black VX1 QB Strain 3W 350 2 Strain 2 Vr1000 2 CR5000 4WFBS350 2 A Common H A Common L B G H pin 2H Lpin 2L Gpin Ground Black vxi QB Strain 3W 350 3 Strain 3 Vr1000 3 CR5000 4WFBS350 3 A Common H A Common L B 6 X Next Finish e Help A TA Y Figure B 21 Sample Wiring Diagram 28 Once the Wiring Diagram has been printed select the Finish button at the lower right corner of the screen The user will be prompted to save the program 124 9 Short Cut CR5000 CACampbellsciiSCWintuntitled scw Scan Interval 1 0000 Seconds gt Bg File Program Tools _ Help Save As OO J 05 C Campbellsci SCWin 4 Search sewin E Organize New folder B y FEE Name z Date modified Type EE Desktop D sys File folder 1 T Downloads generic program SCW SCW File El Recent Places ProgramforCampbell SCW 7PM SCW File L Solar 2 Program SCW SCW File El G Libraries _ Solar Program SCW 22AM SCWFile E Documents WindonSolar scw M SCW File a Music WindSolar Final SCW SCW File Pictures WindSolar SCW 7PM SCWFile B Videos _
96. ient curves However as previously noted the results of these tests provide design values that are not in agreement with one another This discrepancy could be due to many factors including the difficulty in obtaining a proper scaled model that accurately represents the actual stiffness and material properties of the panel itself Tilley 2012 Because of this it is recommended that full scale testing be conducted on flat roof mounted solar panels to validate the pressure coefficients which have been determined from these many wind tunnel studies and provided in the draft report written by the SEAOC subcommittee Full scale testing has been avoided in the past for many reasons For example when conducting a full scale test the researcher is left to wait for Mother Nature to produce sufficient wind gusts which may take a significant amount of time unlike a wind tunnel where the results can be generated in several hours The testing equipment and solar panels are outdoors and therefore are effected by temperature effects such as thermal expansion and contraction of the frame In a wind tunnel study the solar panels can be oriented in many directions and rotated on a turntable to study the effects of wind from all directions in full scale testing the solar panels must be placed in one orientation and location and studied for an unpredictable period of time until favorable results are 20 obtained Despite the complications involved with full scal
97. igure 29 9 1 Roof Mounted Solar Panel Arrays Roofs 057 For values of 4 between 5 and 15 linear interpolation is permitted 16 Nominal Net 1 u Y 30 28 26 u 2 20 u 16 u 12 10 ag 36 au a2 0 10 WO 5001000 5000 Normalized Wind Area A 15 s w s35 North is nomial north besed on panel oriemation North is raised edge for sowth facing panels Edge factor equals maximem of E Ep Ep and Ep Figure 2 4 Design GCp Values Published by SEAOC August 2012 SEAOC 2012 used with permission 18 h lt 60 ft or all heights if A lt W Roofs 0 lt 7 Notes GC acts towards and away from the panels top surface There shall be a minimum air gap around the perimeter of cach solar module of 0 5 inches or between rows of panels of 1 inch to allow pressure equalization above and below panels Altematively for w 0 h lt 10 and air gap per note 2 use components and cladding procedure per ASCE 7 10 30 4 ASCE 7 05 6 5 12 4 Array should not be closer than 2 A Aa or 4 feet whichever is greater from roof edge Roof structure area covered by solar array need not to be designed for simultaneous application of solar array wind loads and roof components and cladding wind loads As a separate load case roof structure shall also be designed for full roof components and cladding wind loads assuming PV panels are not present Notation Effective wind arca for structural ele
98. ing force coefficients applied to solar panels placed on flat roofs For the purpose of this study the panel was intentionally located near the edge of the roof within the shear layer For the limited range of wind directions investigated as part of this thesis the maximum force coefficients were generated when the wind direction was perpendicular to the face of the panel The force coefficients determined from this study are significant Peak force coefficients Cr as much as 18 7 were obtained for wind in the direction perpendicular to the faux solar panel test frame Force coefficients from 9 to 10 were frequently obtained Two additional wind directions were investigated to determine peak force coefficients For a wind direction of 160 degrees 20 degrees from the perpendicular axis to the panel force coefficients as high as 7 2 were calculated For a wind direction of 225 degrees 45 degrees from the perpendicular axis to the panel force coefficients as much as 6 9 were calculated The repeatability study shows that there is good correlation between the force coefficients obtained from this study Additional wind directions should be investigated to further validate this conclusion 7 2 Conclusions As initially anticipated the force coefficients obtained as a result of this study are significant Further investigation should be carried out to determine the values of the 91 peak force coefficients considering only three azimuth angles w
99. l Used to Power the CR5000 Data Logger 4 4 Strain Transducers Six strain transducers were fabricated for use in this experiment the transducers were labeled A F 4 4 1 Strain Transducer Fabrication Each strain transducer was fabricated by mounting a 350Q strain gage to the inside surface of a three inch diameter steel ring as shown in Figure 4 3 below Holes 1 2 inch in diameter were drilled through two sides of the steel ring 90 degrees from the strain gage and 180 degrees from one another Three lead wires were soldered to each strain gage The gages were then covered with small squares of silicone and taped down to the steel ring with electrical tape for protection 35 Figure 4 3 Strain Transducer 4 4 2 Strain Transducer Calibration The strain transducers were calibrated prior to use in the using an MTS machine in the UCD structures lab For calibration purposes one foot long sections of 7 16 inch diameter all thread were bolted to each side of the strain transducer the same material which was used for the diagonal tension ties in the solar panel frame Figure 4 4 shows the strain transducer arrangement in the MTS machine during calibration Once the transducers were calibrated load versus strain curves were developed for each gage The calibration curves for all six of the transducers A F are provided below in Figures 4 5 through 4 10 36 Figure 4 4 Strain Transducer Calibration Set Up Load Ibs 8 8 8 3 8
100. le WS_mph miles hour Vr1000 6 03001 WindDir Sample WindDir degrees 4 7 QB Strain 3W 350 7 of 7 Strain 7 WS_mph_2 Sample WS_mph_2 miles hour 4 03001 WS_mph WindDir 03101 WS_mph_2 1 Table1 2 Table2 Advanced Outputs all tables l Add Table l Delete Table Edit Figure B 18 Selecting the Outputs for each Sensor 25 Once this process is complete there are a couple of items to note If the user is storing data to the PC card Short Cut defaults to storing data to the card every 60 minutes The data will be recorded and saved on the internal memory of the data logger during that interval and then sent to the PC card at the interval selected This means that the current value of each sensor will be recorded on the PC card every hour Should a shorter interval be desired so that you can view your sensors real time while performing testing this value can be changed The data logger will automatically store data to its internal memory which is 2MB Once the internal memory has been filled the data logger will overwrite itself and 120 the data which was previously stored within will be lost Depending on the number of sensors which are being monitored and the sampling interval the 2MB of internal can be filled up rather quickly For example each measurement from each device is 4 bytes Below there are a total of 11 Sensors being monitored at one second intervals That means each seconds measurement f
101. mary of Cr determinations from Figure 6 16 within wind direction tolerance for 3 second rolling averages Cr 3 second Average 11 3 9 4 5 1 4 3 4 1 4 1 3 8 3 5 2 8 2 6 2 5 Zed 2 1 1 9 1 8 1 6 1 6 1 5 1 5 1 3 102 1 2 1 1 1 1 1 1 1 0 1 0 0 9 0 9 0 8 0 7 0 7 0 6 0 6 0 5 0 5 0 5 0 5 0 5 0 4 0 4 0 4 0 4 0 4 0 4 0 3 0 3 0 3 0 2 0 2 0 2 84 6 3 Discussion The 400 second time interval was arbitrarily selected Unlike wind tunnel studies where the wind is constantly coming from one direction of interest in full scale testing the wind directions change rapidly over a short duration of time The the 400 second time interval was selected for the time histories above to illustrate the wind gusts which occurred in the wind direction of interest over that particular 400 second time interval The initial assumption was that the maximum resultant force on the panel would be produced by winds from the northwest which was set to 180 degrees or perpendicular to the panel The force coefficients summarized in Table 6 1 ranged from a minimum value of 0 1 to a maximum value of 18 7 Those force coefficients were based on a 3 second averaging of the measured wind speeds and strains for the time history record shown in Figure 6 1 While several Cr values are relatively high the majority range from approximately
102. ment being designed in ft Ac Normalized wind area equal to Gaza 13 y A 0 5 FW but need not exceed A in ft d Horizontal distance measured orthogonal to the panel edges in the north d south d east d and west d direction from panel being evaluated to adjacent panel or building edge whichever is closer ignoring any rooftop equipment in ft For panels in a row dg and dy are measured from the end of the row in their respective direction E and E apply only to the panels within 5 ft of each end of the row on their respective side and panels greater than 5 ft from both ends of their row shall have d and dy O Array edge factor calculated for each panel area in each principle direction at a time equal to maximum of Ey Es Es Ey If panel area being evaluated is located in zone 2 or 3 and dy measured to building edge ignoring all other panels is greater than 3 aw then E for that panel area need not exceed 1 5 If panel area being evaluated is located in zone 2 or 3 and ds dg or dy measured to building edge ignoring all other panels is greater than 3 an then Es En or Ey for that panel area in only that respective direction need not exceed 1 0 Net pressure coefficient equal to 7 2 GC sa y Nominal net pressure coefficient Mean roof height above ground except for monoslope roofs use maximum roof height in ft Solar panel height above roof at low edge in ft Solar panel height above roof at raised edge
103. modules are for quarter bridge strain gage circuits PC Card Once a program has been created using Short Cut a wiring diagram can be generated The program must then be compiled and sent to the data logger Once the program has been sent to the data logger the user can begin taking measurements The measurements can be monitored in real time with the use of the trend net cable The driver for the trend net cable must be downloaded on your computer prior to use When 99 taking real time measurements from the data logger the user will need to display the Public tables to view the data being measured Graphs can be generated in RTDAQ while data is being recorded The data logger has a small memory Depending on the sampling interval the length of time the data logger will be recording and the number of sensors that are running the memory of the data logger can become full within as little as six hours Once the internal memory of the data logger is full it will begin writing over the existing data stored in its memory The memory of the data logger can be expanded through the use of a 2 GB PC card provided the user added the CardOut sequence in the program Instructions for generating the CardOut sequence have been provided in Appendix C It should be noted that the maximum sized PC card that can be used with the CR5000 data logger is 4GB However throughout the course of this study that increased the time between downloads from 6 hours to appr
104. mpbell Scientific for use with the CR5000 data logger Short cut is an excellent alternative for writing your program due to the fact that all the measurement and control devices have already been stored within the program For those who are not savvy with the language of computer program this user strongly suggests using this means of generating your program Short Cut is accessed through the RTDAQ program which is the software used to send the program to the data logger and monitor collect data Be sure to install RTDAQ prior to creating your program 1 Install RTDAQ The software should be located inside of the data logger enclosure box If you cannot locate the software contact the manager of the UCD Electronics Calibration and Repair lab 102 2 Open RTDAQ To create a program using Short Cut click on the red clock icon or go to Tools Short Cut ll Clock Progem Moni palalliGolesiBala ate Program via Short Cut Datalogger Information Clocks Datalogger Name CR5000 m Datalogger Type CR5000 Datalogger Direct Connect Connection ES COM Port COM6 h 7 Pause Clock Update Datalogger Settings Baud Rate 115200 ir Extra Response Time Os aa Datalogger Time Zone Offset Max Time Online Oh Om Os SetClock hous Om El Datalogger Program Current Program WindSolarFinal_20130337 CR5 Send Program 7 Retrieve Program Disconnected
105. mployed by the design professional can be un conservative in nature and possibly be detrimental to the roof structure More research is necessary to determine design wind loads on solar panels particularly when they are installed on buildings with flat roofs 2 3 Wind Behavior and ASCE7 The basis for the design of any structure for wind loading begins with the determination of the appropriate design wind speed and resulting pressure acting on the structure Typically a design engineer will go to ASCE7 and use the appropriate tables figures and equations to determine the wind force applied to the structure To begin to understand how to determine the design wind pressure for roof mounted solar panels one must understand the basic principles of flow and how the equations tables and figures in ASCE7 were created In 1738 Daniel Bernoulli 1700 1782 published his book Hydrodynamica in which he described the important principles in fluid flow Finnemore et al 2002 Within this book Bernoulli s principle was established which described how the dynamic pressure of a fluid in motion was directly proportional to the density of that fluid and half of the square of the velocity The Bernoulli principle is described below neglecting the static and elevation pressure terms 2 Where p dynamic pressure p density of fluid and V velocity This is the same basic principle used today to describe how wind flow interacts with a bluff body
106. n ties could then be adjusted to account for this force A study of the wind load effects on solar panel arrays could be conducted 94 The panels or test frames could be moved to an entirely different roof located in a particularly windy location 95 REFERENCES American Society of Civil Engineers 2010 Minimum Design Loads for Buildings and Other Structures ASCE7 10 American Society of Civil Engineers 2002 Design Loads on Structures During Construction ASCE37 02 Banks D Merony R Sarkar P Zhao Z and Wu F 2000 Flow visualization of conical vortices on flat roofs with simultaneous surface pressure measurement Journal of Wind Engineering and Industrial Aerodynamics 84 65 85 Campbell Scientific 2007 03001 R M Young Wind sentry set instruction manual Logan UT Campbell Scientific Inc Campbell Scientific 2011 SDM INT8 8 Channel Interval Timer Instruction Manual Logan UT Campbell Scientific Inc Campbell Scientific 2001 CR5000 Measurement and Control System Operator s Manual Logan UT Campbell Scientific Inc Cochran L 2012 Wind loads on solar collectors subcommittee in Minutes of Meeting of Structural Wind Engineering Committee Technical Council on Wind Engineering ASCE March 29 2012 Dowds E K Harris J S Rutz F R 2012 Wind load on solar panel experiment Proceedings of the 3 American Association of Wind Engineers Workshop Hyannis MA Aug 12
107. n v Designed for a strain gage with a nominal resistance of 350 ohms Applies an excitation voltage to a 3 wire quarter bridge strain gage and then z performs strain calculations on the measurement The resulting value is the measured voltage in units of microstrain A gage factor can be entered to gt adjust the measurement result to match expected results OK Cancel Help Measurement Battv culations on the measurement The adjust the measurement result to match Finish Help Figure B 6 Strain Gage Properties Window 8 Next the gage factor will need to be set Click on the Set icon to the right of the Gage factor s shown in the red box in Figure B 6 above A window will open allowing the user to enter the gage factor for each of the strain gages individually The gage factor is located on the packaging which comes with each strain gage The gage factor is typically around 2 0 for the 3 wire 350 ohm strain gages Enter the gage factor for each strain gage if the gage factor is the same for all gages enter the factor 108 next to Strain 1 and then select the Fill Down button to populate the gage factor for each of the gages Press OK when finished Short Cut CR5000 C Campbelisci SCWin untitled scw __Scan Interval 1 0000 Seconds pS O Quarter Bridge Strain 3 wire 350 ohm with 4WFBS350 TIM Version 1 0 B x File Program Tools Help Available Se
108. n_3 1 Vr1000_3 BrZero_3 1 GFAdj_3 0 142 Quarter bridge strain shunt calibration for Quarter Bridge Strain 3 wire 350 ohm with 4WFBS350 TIM measurement Vr1000_3 FieldCalStrain 13 Strain_3 1 GFAdj_3 0 QBSSMode C Known_3 CIndex CAvg GFsR aw_3 0 Zeroing calibration for Quarter Bridge Strain 3 wire 350 ohm with 4WFBS350 TIM measurement Vr1000_3 FieldCalStrain 10 Vr1000_3 CReps 0 BrZero_3 ZMode 0 CIndex CAvg 0 Strain_3 Quarter Bridge Strain 3 wire 350 ohm with 4WFBS350 TIM measurement Vr1000_4 BrFull Vr1000_4 1 mV20 4 1 5 5000 True True 0 250 1 0 Calculated strain result Strain_4 for Quarter Bridge Strain 3 wire 350 ohm with 4WFBS350 TIM measurement Vr1000_4 StrainCalc Strain_4 1 Vr1000_4 BrZero_4 1 GFAdj_4 0 Quarter bridge strain shunt calibration for Quarter Bridge Strain 3 wire 350 ohm with 4WFBS350 TIM measurement Vr1000_4 FieldCalStrain 13 Strain_4 1 GFAdj_4 0 QBSSMode C Known_4 CIndex CAvg GFsR aw_ 4 0 Zeroing calibration for Quarter Bridge Strain 3 wire 350 ohm with 4WFBS350 TIM measurement Vr1000_4 FieldCalStrain 10 Vr1000_4 CReps 0 BrZero_4 ZMode 0 CIndex CAvg 0 Strain_4 Quarter Bridge Strain 3 wire 350 ohm with 4WFBS350 TIM measurement Vr1000_5 BrFull Vr1000_5 1 mV20 5 1 5 5000 True True 0 250 1 0 Calculated strain result Strain_5 for Quarter Bridge Strain 3 wire 350 ohm with 4WFBS350 TIM measurement Vr1000_5 StrainCalc Strain_5 1 Vr1000_5 BrZero_5 1 GF
109. nd the gage factors have been entered select OK at the bottom left corner of the strain gage properties window 10 Once the strain gages have been added you will notice that the Selected Sensor window has been populated with a total of seven strain gages shown in Figure B 8 below Each will be assigned to a separate differential channel for wiring purposes Short Cut automatically assigns differential channels to each device according to the order with which it was entered into the program If for some reason you need to change the 109 differential channel associated with that device you will need to open the CRBasic Editor and change the differential channel to the desired value Note once a program generated in Short Cut has been opened in the CRBasic Editor and saved it can no longer be re opened in Short Cut Finish creating your program prior to opening in CRBasic Editor CRBasic Editor is also located within the RTDAQ software 9 Short Cut CR5000 C Campbellsci SCWin untitledscw Scan Interval 1 0000 Seconds l File Program Tools Help Available Sensors and Devices Selected Progress A Barometric Pressure 2 Sensor Measurement 1 New Open Precipitation 4 CR5000 2 Datalogger Y Relative Humidity amp Temperature Soil Moisture 3 Sensors Pars PTemp_C 4 Outputs 4 Ey Wind Speed amp Direction 4 1 QB Strain 3W 350 1 of 7 Strain 1 5 Finish E aaa L 024A Wind Direction Sensor 1 MESA
110. ng a Thermocouple id 116 Thermocouple Properties Menu O AS 117 Selected Sensors Window ceciciiaiii aiii ai 118 Selecting the Outputs for cache 119 Selecting the Outputs for each SENSO asrisici no contare daniela asiste 120 Selection the Appropriate interval for PCCard Storag6 ooooooccccnncccnoncccnnnccnonnnnnnns 122 Accessing the Wiring Diagram sessesssseessseessressessseessseessseessressensseeesseessseesseese 123 Sampl Wiring Diagram ia 124 lA NT 125 Conecte to the Data Los ES 126 EZSetup Wizard for Connecting to the Data LoOggeT ooooocccnoococnoncccnoncnononcninananos 127 Selecting the Data Logger for the Communication SetUP ocoococnnocccnoncncnonnninnnnnnnno 127 Selecting the Data Logger for the Communication SetUP coocnoconnnnnnocononnnannninnos 128 Selecting the COM Port on your computer coooooccconcccnonancnononcnnnnncnnnnnononanonnncnnnnnnnnnns 129 B28 Saying th Pro grant aida it 130 C 1 Accessing CRBasic Editor in the RTDAQ Program eee eeeeeneecseceneeeeeeeenees 131 C 2 Accessing CRBasic Editor in the RTDAQ Program cece eeeeeseeesteceteeeeeeeenees 132 C 3 Opening an Existing Program in the CRBasic Editor ooooccnoccconccccconcncnoncconananinnnos 133 CA Strain Gage factor uni i 134 C 5 Adjusting the Strain Gage Factor in CRBasic EditOT oooonnncononcnoncnnocnnnoncnoncnnnnnnnnoo 134 C 6 Changing the Desired Output Units in CRBasic Editor eee eeeeceeceseeeeneeeeeees 135 C 7 Data Tables and Editing the
111. nsors an Properties Wiring 2 dia ln Erene i wiring Measurement 1 New Open 4 7 Sensors l 2 Datalogger 9 Generic Me How many QB Strain 3W 350 sensors Max 20 7 8 4 y Geotechnic Battv ae ad Total Bridge Resistance ohm 510 irene c 4 Outputs 44 Strain G 5 Finish Q Full 8 Excitation Voltage mv 5000 Calculate Q Full B Q Full B Gage factor s Wiring L Half Bi B Fill Down Wiring Diagram 5 Hea B Half Bi Wiring Text Q Quart Measurement Gage factor s Q Quart Strain 1 2 0 1 Quar Strain 2 D VTI ECI S E Meteorologii kaa i LU Miscellane ser e Strain 4 Temperaturi Water Settling ti Strains Ea Calculations amp Strain 6 ets Devices Strain 7 cancel offsets CR5000 Do Not Group Designed for a strain gage with a nominal resistance of 350 ohms Select Zeroing Calibration Group alculations on the measurement The Applies an excitation voltage to a 3 wire quarter bridge strain gage and then o adjust the measurement result to match performs strain calculations on the measurement The resulting value is the gt measured voltage in units of microstrain A gage factor can be entered to gt adjust the measurement result to match expected results Finish Help OK cancel LI Help Figure B 7 Setting the Gage Factor in the Properties Menu 9 Once the gages have been added a
112. nvert gt Dir ine ct bot Cus Pause Clock Update Dat CRBasic Editor Ea PERRAS Datalogger Time Zone Offset M Set Clock onows Om El Device Configuration Utility O hours Om E LogTool AN Datalogger Program Curent Frogiam 2 WindSolarFinal_20130337 CR5 Disconnected a 2 07 PM a lr i e Pra 4 5 27 2013 Figure C 2 Accessing CRBasic Editor in the RTDAQ Program 2 Once CRBasic Editor has opened go to the file menu and press open and select your program In this case the file name for the program is Example Once your program has been selected press open at the lower right corner of the screen to open your program in CRBasic Editor 132 CRBasic Editor Example CRS for the CR5000 a olf X File Edit View Search Compile Template Instruction Goto Window _ Tools Help 5 x O Open OO JE 0S C Campbellsci SCWin y 49 Search scwin E Organize w New folder E Pee a i Date modified y mi BH Desktop i ala E HElse a ip Downloads p 5 V Elself E Recent Places 3 CRS File real Program for Campbell CR5 0 21 57PM CR5 File amp E Libraries Solar2Program CR5 M CR5File E Documents Solar Program CR5 22AM CR5 File 7 dl Music untitled CRS 56PM CRS File Pictures L WindSolar Final CRS 3 11PM CR5File a E Videos L WindSolar CR5 2 3 M CRS File 1 WindSolar_6Gages CR5 3 27AM_ CR5 File E
113. of the solar panels From these measurements force coefficients were derived The results of this study were presented at the 12 Americas Conference on Wind Engineering in Seattle WA June 16 20 2013 Harris et al 2013 13 Outline There are seven chapters in this thesis The first chapter provides an overview and includes a description of the goal of this research Chapter 2 is a literature review of the history of solar energy and a brief overview of wind interaction on a bluff body The standard used to determine wind pressures is discussed as well as a summary of several wind tunnel studies which have been previously conducted In Chapter 3 the design location and installation of the faux solar panel test frames are discussed Chapter 4 is a summary of the instrumentation and equipment used to conduct this research In Chapter 5 the theory and methodology established to determine the appropriate force coefficients is explained Chapter 6 presents the results of this research from three different wind directions and a discussion of the findings is presented Chapter 7 presents a summary of the results of this study and offers conclusions based on these results A discussion of possible sources of error is made and also presented are recommendations for future research Appendix A provides some basic instructions regarding the usage of the CR5000 data logger In Appendix B a brief instruction on how the program used for this researc
114. ofed structures will have to be adjusted by several factors to determine the appropriate value to use for design This same methodology will be used to produce design curves and external pressure coefficients and other factors that are suitable for the design of solar collectors on buildings with flat roofs 2 4 Wind Tunnel Studies The first wind tunnel study concerned with solar collectors was conducted at the end of the 1970 s in Bucharest The focus of the study was on ground mounted solar panels It was determined that when solar panels are placed in an array or groups the collectors located in the middle of the array were shielded by the collectors that were installed in the first row Radu 1986 This research was continued in the boundary layer wind tunnel at Colorado State University CSU Further research at CSU determined that arrays of solar panels experienced smaller forces than individual panels This particular study also determined that when solar panels were mounted in an array there is a significant force applied to collectors caused by the channelization of wind flow between them Radu 1986 At Texas A amp M University one of the first studies was conducted concerning arrays of solar collectors mounted on flat roofs of existing buildings The study concluded that the first line of solar collectors provided a shielding of successive rows of collectors in the array However it was later noted that there was no satisfacto
115. orded wind velocity could be captured 92 It is possible that the 3 8 inch plywood that was used to simulate the surface of the solar panel was overly flexible under some wind conditions Thus when the plywood was faced with the maximum gust wind speeds it may have deflected and affected the horizontal force component in the diagonal member Therefore the measured strain values may be lower than anticipated This would suggest the Cr values presented above particularly for higher wind velocities may be low Sand bags were used to weigh down the ends of the solar panel frames as a means to hold down the panels without directly connecting them to the roof of the building Due to the weight required to resist the uplift forces the height of the stacks of sand bags was roughly equal to the height of parapet Therefore the sandbags may have interfered with the recirculation flow below the shear layer possibly affecting the Cr value calculated It is possible that the post processing technique could be improved Alternate methods of averaging could be explored 7 4 Recommendations for Future Research There are numerous opportunities to expand on the research presented within this thesis One suggestion is to move the solar panels to a different location on the same roof There are several locations which would yield interesting results for comparison such as further from the edge of the roof where one would expect a lower force coefficient to
116. ows Vista or Windows 7 operating systems For the purposes of this experiment a Dell Inspiron 5423 Laptop was used with Windows 7 as the computer s operating system Short Cut and CRBasic Editor Campbell Scientific 2001 were used to create the program used to record the measurements from the strain gages anemometers thermocouple and the wind direction sensor Both Short Cut and CRBasic Editor were provided with the RTDAQ 1 1 software to be used in conjunction with the CR5000 data logger A brief instruction for use of the CR5000 data logger has been provided in Appendix A Instructions to create a program in Short Cut are provided in Appendix B and instructions to edit the program in CRBasic Editor are provided in Appendix C The program created in Short Cut and edited in CRBasic Editor is provided in Appendix D The data tables generated by the program listed a record number date and time stamp strain output from the five strain transducers wind direction wind speed from the three anemometers and the ambient air temperature 44 5 Theory 5 1 Introduction Numerous wind tunnel studies have been conducted to determine various design parameters for individual solar manufacturers When a wind tunnel study is performed typically pressure taps are used to directly measure the pressure distribution across the face of the panel The pressure coefficient C can be determined by calculating the net pressure across the upper and lower surfac
117. oximately two weeks Downloading Data Data can be downloaded from the data logger by using the trend net direct link cable Note that downloading times are significant for this means of data retrieval If the user has chosen to use the PC Card the PC Card can be removed from the data logger and the data can be retrieved from the PC card directly Prior to removing the PC card from the data logger the user must stop the program from running and uninstall the PC card from the data logger This is done through the main screen on the data logger menu When retrieving data from the PC Card the file must be converted using the Card Convert option available in RTDAQ Once the data is converted it may be 100 desired to open the data file in a program such as Excel If data has been recorded for a long period of time once the file is converted it may not open in Excel This is due to the fact that the maximum number of rows in Excel has been exceeded If this is the case save your file in notepad and then copy the data manually from notepad to Excel Note that your data will have to be split into several files to meet the file size limits in Excel 101 B Creating a Program Using Short Cut B 1 Introduction To aid future students with their research a brief instruction on generating a program using Short Cut which is used with the CR5000 data logger has been provided below B 2 Instructions Short Cut is a program that was provided by Ca
118. r I SOWEIVIEW i ctict hd acu eee Ga tae slab EEEE AEAEE AE SEAE h 1 11 RO GUCHION c 2accdstes it ita sida ue cas 1 Ds A aL aah tia O 2 2 History of Solar Enetpy on A cs 4 Del IntroducliON vusiiralci larisa nea ados 4 22 Historyof S lar Er A A Ad 4 2 3 Wind Behavior and ASCER 7 24 Wind Tunnel Studies o A A AA E AA 10 2 6 Conclusion 20 3 Panel Design Location and Installation ooonncnnnoninnononcnoncnnannconncconocnnnnnnn non ncnoncnnnos 22 3A Descriptio M tan 22 Dee Wind Ll a 24 3 3 Design CalculatiGns ui EA E E E E T E E Ri 26 34 Paux Solar Panel Test trame noice eA EA a esii ea aat 27 3 5 Connection Detalles aa tii 29 3 6 Assembly and TA AAA A eae 31 4 MAS PEW TINE AUT ON EN roe hie tet na acca a Actress ane Mania A eg Mears oe 33 A T TOO CA A A ca ate A das ee A 33 4 2 Data Log A is 33 A a uecea E 3s esas porate clad AR R 34 4A Strain LOSE il pyro ee bee Meee dal 35 AAT Strain Transducer Fabrication iS Adi 35 4 4 2 Strain Transducer Calibration ess di ia 36 4 4 3 Strain Transducer Installation 0 tds 40 4 5 Ane A O S E E E esa paint E S 41 4 0 Wmd Direction Sensor neriie A EAE ea 42 47 Th rmocouple 1 a EE a RE E E E E ASES 43 AS Interval Time esusen a a E A E E A 44 49 A E aia se a aoni aaia etes ae a geo tit AE 44 Y SUS OT V oa a a a a a A a Qeam ties 45 viii Deli TnthOduCt Oni utes EE E EENE AE edad ateden We decode 45 5 2 Wind Interaction with the Panel iia A Aa 45 E A e a eatin es aS 47 6 Results
119. r or near the edge of a flat roof In fact the SEAOC document explicitly states that panels should be placed away from the edge of the roof at a minimum distance of four feet or twice the distance between the height of the panel and the height of the parapet whichever value is larger In this case that minimum distance would be approximately 7 5 feet For this study the panels were placed four feet from the edge of the roof intentionally because it was desired to investigate a worst case condition In order to investigate the validity of this study and determine if the results were reliable a repeatability study was conducted The goal of the repeatability study is to determine if the same net peak force coefficients are obtained when the study is carried out at a different time In order to determine the net peak force coefficients for the panels the top 10 maximum values were averaged for each of the time histories plotted above for a particular wind direction Xypnitou 2012 It should be noted that some of the time histories were plotted from data that was obtained on the same day however in most cases hours of time passed between the time history plots since the data was recorded over a 24 hour period The results were favorable For the seven time history diagrams plotted using the 3 second averaging of wind speeds from the 180 degree direction the force coefficients are as follows 87 Table 6 16 Summary of Net Peak Cr determinations f
120. r the strain 136 gages is set to IEEF4 This corresponds to the recorded strain values to be in four byte floating point format This means that the accuracy of the recorded strain values will be to four decimal places The file size is 4 bytes It is suggested that strain values be recorded to the IEEF4 level of accuracy Note that the weather vane anemometers and the temperature are set to the FP2 or two byte floating point format This means that the recorded values for the wind direction wind speed and temperature will be two bytes in size and to an accuracy of two decimal places Should greater accuracy be desired this value could be adjusted to the IEEE4 format CRBasic Editor Example CR5 for the CR5000 i ls cli File Edit View Search Compile Template Instruction Goto Window Tools Help ATERACO ERATE rears ee DataTable Table1 True 1 DataInterval 0 1 Sec 10 Pe Sample 1 Strain 1 IEEE4 Sample 1 Strain 2 IEE FP2 Two byte Floating Point Gee 2 Sample 1 Strain 3 IEE p k ora taria al IEEE4 Four Byte Floating Point peed q Sample 1 Strain S IEE UINT2 Two byte unsigned integer HIF 3 Sample 1 Strain 6 TEE UINT Four byte unsigned integer is E Sample 1 Strain 7 IEE if E bal Sample 1 WS_mph FP2 String ASCI string Hi Sample 1 WindDir FP2 Boolean True False lye Sample 1 S_mph_2 FP2 Bool 1 bite Boolean Ja Sample
121. rection The equation for the resultant force from the measured Strain Fr is calculated as follows cos Fp T nor 5 1 Where Fr resultant force on panel T force in diagonal tension tie measured from strain transducers O angle of tension tie and 0 tilt angle of panel as shown in Figure 5 3 From the measured wind velocity the resultant force on the net area of the panel due to the dynamic pressure from the wind velocity is determined by equation 5 2 below An instrument was not available to measure the barometric pressure therefore the uncorrected barometric pressure was obtained from the National Climactic Data Center website using the data measured at Denver International Airport which was considered to be the closest weather station U S Department of Commerce 2013 As with the Fr calculations Fel press Was calculated using the difference between two measured velocity 48 readings two seconds apart V A Fyet press E 5 2 Where p density of air uncorrected for altitude V wind velocity averaged over a three second interval and A net area of panel surface The force coefficient Cr is determined from the ratio of the resultant force measured from the strain transducers and force due to the velocity pressure Fr Cr 5 3 Where Cr net force coefficient Fr resultant force on panel and Fei press the force on the panel from the dynamic pressure from the wind The Cr was calculated based on th
122. res the use of multiple anemometers you must add those individually To do this follow the same steps above Select the desired units of measurement in the properties menu for the anemometer In this case the desired units of measurement for wind speed were miles per hour Press OK at the bottom right corner of the properties window 113 9 Short Cut CR5000 C Campbelisci SCWin untitled scw Scan Interval 1 0000 Seconds MES File Program Tools Help Available Sensors and Devices Selected Progress gt 4 Barometric Pressure z Sensor Measurement S 1 New Open 3 Precipitation 4 Default Battv 2 Datalogger Relative Humidity amp Temperature die i Soil Moisture i Prape CAMS i Solar Radiation 03101 Wind Speed Sensor Version 2 6 Strain 1 4 Outputs 4 Wind Speed amp Direction Vr1000 1 ini 014A Wind Speed Senso E 5 Finish Q ind d Properties ijg Strain 2 L 024A Wind Direction Se 03001 Wind Speed amp Di Wind Speed WS_mph mies nour y vr1000 2 Wiring Q 03002 Wind Speed amp Dirt meters second Strain 3 Wiring Diagram _ 03101 Wind Speed Sens kilometers hour Vr1000 3 A Q 03301 Wind Direction Se Wiring Text Q 0344 0348 Wind Speed knots Strain 4 Q 05103 Wind Speed amp Dir Vr1000 4 Q 05106 Wind Speed amp Dir Strain 5 D 05305 AQ Wind Speed 8 Vr1000 5 Q 27106T Wind Speed Sel Q CS800 Wind Speed amp Di Strain 6 NRG 20
123. rom Figures 6 1 and 6 4 through 6 9 within the 180 degree wind direction tolerance for 3 second rolling averages Crpeak Figure Number Table Number 57 6 1 6 1 4 0 6 4 6 3 5 3 6 5 6 4 4 1 6 6 6 5 4 9 6 7 6 6 5 2 6 8 6 7 5 3 6 8 6 8 A similar trend was seen for the alternate wind directions investigated For a wind direction 20 degrees from the perpendicular axis of the panel peak force coefficients ranging from 3 6 7 2 were obtained For the wind direction 45 degrees from the perpendicular axis of the panel peak force coefficients ranging from 3 5 6 9 were calculated A summary of the net peak force coefficients obtained from the 160 degree 20 from the perpendicular axis of the panel and 225 degree 45 from the perpendicular panel axis wind directions has been provided below in Tables 6 17 and 6 18 88 Table 6 17 Summary of Net Peak Cr determinations from Figures 6 10 through 6 13 within the 160 degree wind direction tolerance for 3 second rolling averages C peak Figure Number Table Number 54 6 10 6 9 5 1 6 11 6 10 5 1 6 12 6 11 4 5 6 13 6 12 Table 6 18 Summary of Net Peak Cr determinations from Figures 6 1through 6 16 within the 225 degree wind direction tolerance for 3 second rolling averages C peak Figure Number Table Number 46 6 14 6 13 5 3 6 15 6 14 5 1 6 16 6 15 The force coefficients obtained from this full scale test are reasonable The response of the solar panel test frame was a
124. rom the 11 output devices is 44 bytes Therefore the internal memory of the data logger will be filled in approximately 13 2 hours If the user does not wish to download data twice per day the CR5000 is equipped with a 2 GB external Compact Flash Card To store data to the card check the box next to PCCard above the Selected Outputs Window Check the box next to CSI O to USB Flash Memory drive This will allow you to retrieve data from the data logger using the provided cable Instructions for downloading data can be found in Appendix A 121 O Short Cut CR5000 C Campbellsci SCWin untitledsew Scan Interval 1 0000 Seconds MC aa ba y a File Program Tools Help Selected Sensors Selected Outputs Progress J Sensor Measurement Average Table Name frablez 1 New Open 4 CR5000 Maximum Z MODUS Battv Store Every 1 3 Sensors 7 PCCard Microseconds PTemp_C Milliseconds gt 4 Outputs 41 QB Strain 3W 350 10f 7 _Strain 1 Y SC115 CS 1 0 to USB Flash a Minutes 5 Finish Vr1000 1 Sensor Measureme Hours 4 2 QB Strain 3W 350 2 of 7 Strain 2 TEs QB Strain 3W 350 Strain 1 Day microstrain pb Vr1000 2 WindVector QB Strain 3W 350 Strain 2 Sample Strain 2 microstrain Winks Diagram Stan SW SO 057 ada QB Strain 3W 350 Strain 3 Sample Strain 3 microstrain Wiring Text Vr1000 3 gt a QB Strain 3W 350 Strain 4 Sample Strain 4 microstrain 4 4 QB Strain 3W 350 4 of 7 Strain 4 z
125. ry 10 attempt was made to simulate the boundary layer and the building on which the collectors were mounted Radu 1986 In 1984 additional research was conducted in the wind tunnels of Issay Romania Radu 1986 This research was primarily concerned with the determination of pressure coefficients on the surface of solar collectors mounted on the fat roofs of five story buildings The five story building was modeled with a rigid diaphragm and the building and solar collector panels were scaled to 1 50 The panels were mounted at the center of the roof with a 30 tilt angle with respect to the horizontal roof surface The wind direction was measured from 0 to 360 Pressure taps were installed on the upper and lower surfaces of the collector panels to determine the net pressure applied to the surface of the collector Pressure taps were also installed on the building roof surface and the walls in order to facilitate a comparison between measured pressure coefficients and the values provided by the building code An urban exposure category was idealized in the boundary layer wind tunnel so that the pressure coefficients measured could be compared to other studies Smoke was introduced wind tunnel Figure 2 2 and it was observed that as the air collided with the windward face of the building at the roof level the passage of horizontal air streams was prevented giving rise to a shelter effect for the first rows of solar panel collectors
126. s initially predicted This is evidenced by the time history diagrams strain peaks with wind gusts and ultimately peak force coefficients determined by the repeatability study Note that in the time history diagrams 6 1 and 6 3 through 6 16 each time a gust occurs there is a peak in the Wind Velocity diagram In conjunction with the peak gust there is a corresponding peak in the 89 measured strain in the tension ties Tables 6 16 through 6 18 show that the results of the net peak force coefficients are within good agreement There is little variation in the force coefficients calculated when the wind direction was 160 and 225 degrees There is some slight variation in the peak force coefficients calculated from the 180 degree wind direction This could be due to the two high Cr values from Table 6 1 and 6 7 However there appears to be good correlation of the peak force coefficients from the other time history plots There is sound correlation between the values of the force coefficients obtained using the full scale solar panel test frame used for this study For the limited range of wind directions investigated as part of this thesis the maximum force coefficients are generated when the wind direction was perpendicular to the face of the panel 90 7 Summary Conclusions Possible Sources of Error and Recommendations for Future Research 7 1 Summary A full scale faux solar panel test frame was developed for the purpose of obtain
127. se of the panel legs to connect them to a wood 2x6 laid flat The heads of the bolts were countersunk into the bottom of the 2x6 to prevent damage to the surface of the roof 29 3 PLYWD COUPLER e 9 BOLT 7 16 THREADED ROD L TS1x1x16GA CABLE 2X6 L PAVERS E ROOF w BOLT COUNTER BORE OR COUNTER SINK Figure 3 8 Panel Frame Connection Details at the Diagonal Tension Ties ae es 3 PLYWD 2x6 EA LEG X BRACING PAVERS E ROOF BALLAST Figure 3 9 Panel Frame Connection Details in the Short Dimension 30 ee PLYWD ie BOLT LAT JE EYE BOLT X STL TUBE 4 2x6 LL ren E ROOF e N f Figure 3 10 Close Up View of Short Direction Panel Frame Connection Details 3 6 Assembly and Installation Prior to construction shop drawings were produced for the steel components of the panel frame and provided to the Electronics Calibration and Repair Lab at the University of Colorado Denver The steel components were fabricated according to the shop drawings The panels were assembled prior to installation on the roof of the Events Center Building Once the panels were assembled cable cross bracing was installed in the short direction of the panel legs The cross bracing provided stability of the frame in the short direction of the panel Once the panels were assembled they were transported to the roof of the Events Center building where they were placed upon a 10
128. ss 2012 March 29 31 Chicago Il American Society of Civil Engineers Reston VA Tilley C 2012 Why current module frame based mounting systems are inadequate Structure Magazine vol 19 no 7 National Council of Structural Engineers Associations C3 ink Publishers Reedsburg WL July U S Department of Commerce 2013 National Oceanic amp Atmospheric Administration 2013 Quality controlled local climatological data hourly observations table QCLCD Denver International Airport 03017 Denver CO 4 2013 lt http cdo ncdc noaa gov qclcd QCLCD gt April 18 2013 U S Department of Energy 2006 Laying the Foundation for a Solar America The Million Solar Roofs Initiative Final Report lt http www nrel gov docs fy07osti 40483 pdf gt accessed November 21 2012 U S Department of Energy The History of Solar lt http www1 eere energy gov solar pdfs solar_timeline pdf gt accessed November 21 2012 Xypnitou Eleni 2012 Wind Loads on Solar Panel Systems Attached to Building Roofs M S Thesis Concordia University Montreal Quebec Canada 97 A Campbell Scientific CR5000 Data Logger Information A 1 Introduction A brief guidance for use of the Campbell Scientific CR5000 data logger has been provided below The purpose of this Appendix is not an explicit user guide but rather some helpful hints for students just beginning their research Refer to the Campbell Scientific CR5000 Me
129. then ask the user to sync the data logger with the clock on your computer Once this has been completed the setup wizard will ask the user 1f he she would like to send the program to the data logger Press yes and navigate to your program Once this has been completed the wizard will tell you if your program was successfully sent to the data logger Once this has done you will be taken back to the Home screed in RTDAQ and the program name will appear on the right hand side as shown in Figure B 28 below 129 r 1 7 RTDAQ 11 Datalogger Support Software CR5000 CR5000 folle Es File Datalogger Network Tools Help am 3 OB 6190000 Clock Program Monitor Data Collect Data a A Datalogger Information Clocks cR5000 Datalogger Name CR5000 Datalogger Type CR5000 Datalogger PC Direct Connect Connection COM Port COM6 Pause Clock Update Datalogger Settings Baud Rate 115200 Extra Response Time Os Max Time Online Oh Om Os Datalogger Time Zone Offset Datalogger Program Current Program 5 gages 20130601 CR5 Retrieve Program Disconnected Figure B 28 Saving the Program 35 After this process has been completed one time the next time the user opens RTDAQ the data logger will automatically appear in the upper left hand corner of the screen as shown in Figure B 28 above When connecting with the data logger after this point simply install the trend net cable in the data log
130. ties over the same time interval _ 2 T T cos0 F v2 Vv2 p Asin p 5 4 Where Cr net force coefficient T force calculated from the measured strain in the tension ties O angle of tension tie and 0 tilt angle of panel p density of air and V wind velocity The thermal effects on the steel elements of the panel frame as well as the thermal output of the strain gages are considered to be negligible over the short duration The tilt angle of the panel the angle of the tension tie the barometric pressure and the panel area are all known quantities Thus the force coefficient is directly proportional to the change in strain over a two second time interval divided by the change in the velocities squared over the same two second time interval shown in equation 5 4 The two second interval was arbitrarily selected for convenience It should be noted that the velocities used to calculate the force coefficients were averaged over a three second interval and correspond to a 3 second gust wind speed Therefore the Cr calculated using equation 5 4 is inclusive of the gust effect factor G The term Cr was used rather than GCr because the force coefficients were determined from direct measurements and therefore the gust effect factor G was assumed to be equal to 1 0 51 Initially it was assumed that the largest force coefficients would be obtained when the wind direction was perpendicular to the panel The data was filtered so t
131. tion Sensor A single RM Young 3301 Wind Sentry Vane was mounted to a cross arm attached to a 34 diameter schedule 40 pipe located well above the shear layer with the associated anemometer Figure 4 13 shows a view of the experiment setup 42 Anemometer Figure 4 13 Overview of Anemometer and Vane Installation 4 7 Thermocouple Campbell Scientific A3537 Type T thermocouple wire was used to record the ambient air temperature The recorded temperatures were then compared with the daily reported temperatures gathered from the National Climatic Data Center records U S Department of Commerce 2013 to confirm the accuracy of the readings The Type T Thermocouple is made from a copper and constantan wire The thermocouple wire was 2 feet long and routed outside of the data logger enclosure box to record the ambient air temperature rather than the panel temperature within the data logger enclosure 43 4 8 Interval Timer An SDM INTS interval timer manufactured by Campbell Scientific was used to capture wind speed data from the third anemometer The interval timer has eight channels which can be programmed to output processed timing information to a CR5000 data logger Campbell Scientific 2011 4 9 Software RTDAQ 1 1 software provided by Campbell Scientific was used with the CR5000 data logger to record all measurements RTDAQ 1 1 Campbell Scientific 2001 1s compatible with computers running Microsoft Windows XP Wind
132. ue da 4 Default Battv a Datalogger gt elative Humidi emperature 3 Soil Moisture PTemp_C 3 Sensors 3 Solar Radiation 4 1 QB Strain 3W 350 1 of 7 Strain 1 4 Outputs a Wind Speed amp Direction Vr1000 1 5 Finish a Ea pap Seaan 42 QB Strain 3W 350 2 of 7 Strain 2 L 03001 Wind Speed amp Direction Sensor Vr1000 2 Wiring 1 03002 Wind Speed amp Direction Sensor 43 QB Strain 3W 350 3 of 7 Strain 3 Wiring Diagram 03101 Wind Speed Sensor Vri000 3 5 L 03301 Wind Direction Sensor Wiring Text 1 0344 0348 Wind Speed amp Direction Sensor lia 4 4 QB Strain 3W 350 4 of 7 Strain s Q 05103 Wind Speed amp Direction Sensor Vr1000 4 Q 05106 Wind Speed amp Direction Sensor 4 5 QB Strain 3W 350 5 of 7 Strain 5 a 05305 AQ Wind Speed amp Direction Sensor vr1000 5 Q 27106T Wind Speed Sensor E 7 z Q CS800 Wind Speed amp Direction Sensor 4 6 QB Strain 3W 350 6 of 7 Strain 6 L NRG 200P Wind Direction Sensor Vr1000 6 L NRG 40 Wind Speed Sensor 4 7 QB Strain 3W 350 7 of 7 Strain 7 L WindSonic4 SDI 12 Two Dimensional Ultrasonic Wind Sensor A Miscellaneous Sensors La Temperature 0300 Ww LA Water Calculations amp Control CR5000 RM Young Wind Sentry Wind Speed Sensor a Units for Wind Speed miles hour meters second kilometers hour knots 4 Previous Next gt Finish Help 1334M 5 26 2013 Figure B 11 Adding additional Anemometers 16 If the user requi
133. ulation eee ceeceeseeeneecsseceseeseeeesaeecsaeenseeees 52 6 1 Wind Velocity Strain and Calculated Cr Values from 4 14 13 Data oononnnnnnn 55 6 2 Results of Wind Direction Plotted Versus Cr from April 14 2013 oe eee 57 6 3 Wind Velocity Strain and calculated Cr Values from 4 14 13 Data eee 58 6 4 Time History of Wind Velocity and Strain with Corresponding Cp cccoocccconccnnonnnn ns 60 6 5 Time History of Wind Velocity and Strain with Corresponding Cp ccccoocccconcccnonnni ns 62 6 6 Time History of Wind Velocity and Strain with Corresponding Cp cccooccccnncccnonnnn ns 64 6 7 Time History of Wind Velocity and Strain with Corresponding Cp ccccoccccnncccnnoncninns 66 6 8 Time History of Wind Velocity and Strain with Corresponding Cf eee 68 6 9 Time History of Wind Velocity and Strain with Corresponding Cp cccooccccnccccnonnni ns 70 6 10 Time History of Wind Velocity and Strain with Corresponding Cf e eee 72 6 11 Time History of Wind Velocity and Strain with Corresponding Cf cece 74 6 12 Time History of Wind Velocity and Strain with Corresponding Cf e eee 76 XV 6 13 Time History of Wind Velocity and Strain with Corresponding Cr ccooccccnccccnonnnn no 77 6 14 Time History of Wind Velocity and Strain with Corresponding Cf eeeeeeees 79 6 15 Time History of Wind Velocity and Strain with Corresponding Cr cnoconnccnnoncconnnnno 81 6 16 Time History of Wind Velocity and Strain
134. un s energy to power and generate electricity The photovoltaic cell was created from a piece of silicon which contained a trace amount of gallium and lithium and was approximately five times as efficient as the selenium solar cells used at the time Perlin 2004 Over the next several decades many technological advances were made to increase the efficiency of photovoltaic cells By the mid 1960 s NASA created solar powered space crafts and observatories The world s first solar powered residence was constructed in 1973 by the University of Delaware Named Solar One the residence employed the use of a roof top solar array to provide power to the residence throughout the daytime History of Solar 2012 Between 1997 and 2005 the Million Solar Roofs program was initiated Solar America 2006 The goal of this group of volunteers was to facilitate the installation of a specified number of solar roofs As part of this initiative in 2000 a large solar residence was constructed in Morrison Colorado This 6 000 square foot home that employed the use of solar energy to power the residence for the family The technological advances in solar energy over time have made it more affordable and accessible for homeowners and businesses to consider solar energy as an alternative power source As our society begins to realize the impact that we have made on our ecosystem with the use of coal fueled electric plants etc people have begun to

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