User Manual - Dynaflow, Inc.
Contents
1. Rezan 0 024 ms 0 024 ms i start W box 3 win JoynaFS DD 4 Armis M Abs Mi Figure 17 Display of sent and received signals under Cavitation Susceptibility mode 4 5 Analyze k For the No hardware version under the regular ABS mode this button invokes the analysis algorithms that reprocess the saved signal data and uses the analyzed acoustic signals to obtain the measured bubble populations The results are automatically displayed on the screen Figure 18 described below under 4 6 View Results This function can also be invoked by selecting Experiment Analyze Signals or pressing the F9 key Under Cavitation Susceptibility mode this button invokes the algorithms that process the acoustic signals to obtain variation of the filtered received signal with voltage and the determined threshold of cavitation 33 ABS Acoustic Bubble Spectrometer USER MANUAL 7 086 v 6 0 4 6 View Results L This button activates the View Results mode to display the analysis results of the experiment Figure 18 It is automatically enabled after clicking the Analyze h button or can be activated by clicking the View Results hi button at any time In the No hardware version both Analyze and View Results hi buttons will display the analyzed resulst howerver View Results ki button will not re analyze the saved signals and uses only the saved u and v information to obtained the measured bubble populations2. 03 31 06 test 2 abs ABS Acoustic Bubble Spectrometer Fie Edit Experiment View Heb ABS Acoustic Bubble Srectrometen 1995 2006 www dyneflow ine com Du ar ig n A e i 91 Sound Speed Ratio Usc siqic Attenuation V 1 0 45 1 D4 1 98 35 0 96 03 2 094 0 25 2 02 64 0 15 0 090 0048 i 15 4 65 9 115 140 165 19 215 15 40 65 wW 15 140 165 190 215 Frequency KHz Frequency kHz Bubble Size Distribution Total Void Fraction 3 49e 005 160 8 58 2 215 0 00 il li a ae 14 034 55 75 136 156 165 Buddie adi AOA Dyna d 7 D36_J dDowument BMgoxfFo 9 2 Widow v Figure 18 Display of the Analyzed Results The following descriptions applied to the regular ABS mode Four plots are displayed in this mode e Sound speed ratio u C Cc ef vs frequency e Attenuation ratio v vs frequency 34 ABS Acoustic Bubble Spectrometer USER MANUAL 7 086 v 6 0 e Bubble size distribution in the form of the number of bubbles per cubic centimeter vs bubble radius in microns e Void fraction contribution in the form of the void fraction contribution vs bubble radius in microns The total void fraction of all bubbles are also displayed above the graph it is simply the total measured void fraction in the range of bubble size detected Note The number of bubbles per cubic centimeter is plotted on the vertical axis of the bubble size distribution To obtain the n
3. Thermal Conductivity k aT b ae 5 5286 005 poes Figure 9 Experimental Settings Physical Parameters Page a Physical Parameters The Physical Parameters page Figure 9 specifies the operating conditions of the experimental environment These data are to be entered in S7 units as noted on this page and should be specified for the temperature and pressure at the measurement location Values to be specified include e Pressure static of the liquid at the measurement location Pascal Temperature of the liquid at the measurement location C Specific heat ratio c c of the gas comprising the bubbles Vapor pressure of the liquid Pascal Sound speed in the pure liquid no bubbles m s Liquid density kg m Liquid surface tension N m Liquid dynamic viscosity kg m s Gas thermal conductivity k given as a linear function of temperature T K with parameters a and b W m K 24 ABS Acoustic Bubble Spectrometer USER MANUAL 7 086 v 6 0 k aT b A database for the frequently used liquids such as water mercury mineral oil corn syrup etc is listed for convenience If the liquid of interest is not listed in the database please select user specified and enters the customized physical parameters as required Experiment Settings General Signals Physical Parameters Physical Constraints Bubble Size Information Number of Sizes 100 Use Logarithmic Scale On TT Ony Radius
4. C Linear frequency list Arrange frequency list automatically Freq Hz Ref Gain TestGain Ignore Signal V Factor Ref V Factor 10000 No 1 00 1 00 10100 No 1 00 1 00 10200 No 1 00 1 00 10300 No 1 00 1 00 10400 1 00 1 00 10600 1 00 1 00 10700 1 00 10900 i 1 00 11000 1 1 00 11100 l 1 00 11300 j 1 00 11500 ij 1 00 11600 1 00 11800 1 00 11900 1 00 12100 1 00 owes Figure 8 Experimental Settings Signals Page ENABLE SIGNAL SETTINGS AUTO CALIBRATION Since the gain and voltage settings can be different for each frequency as well as for test and reference signal It is tedious to manually set up the gain and voltage setting manually The user can check Enable Signal Settings Auto Calibration to let the system figure out the best gain and voltage settings for each frequency in both test and reference condition After checking this option when acquiring reference signal the system will continuously adjust the gain and voltage settings until optimal settings have been found for all frequencies then the real reference signals will be acquired at the 20 ABS Acoustic Bubble Spectrometer USER MANUAL 7 086 v 6 0 settings optimized When measuring the first time under the test conditions the system will similarly adjust the gain and voltage settings until optimal settings have been found for all frequencies then the real test signals will be acquired at the settings optimized After the calibration for t
5. Minimum 10 microns Maximum 1000 microns Area of bubbles per m 3 of mixture 100000 Volume of bubbles per unit volume of mixture 100000 Cancel Figure 10 Experimental Settings Physical Parameters Page a Physical Constraints On this page Figure 10 physical constraints are imposed in order to enable solution of the ill posed problem and the parameters of the computed distribution are specified These include the minimum and maximum of the computed bubble sizes radii and the number of discrete sizes to compute Two options are available for calculation and subsequent display of the bubble sizes The sizes can either be linearly or logarithmically distributed between the minimum and maximum sizes In addition the vertical scale y bubble number per unit volume can be displayed with either a linear or logarithmic scale The logarithmic scale is selected if the appropriate box on this page is 25 ABS Acoustic Bubble Spectrometer USER MANUAL 7 086 v 6 0 checked Upper bounds on both the total bubble surface area and the total bubble volume per unit volume m of the measurement region are also specified here These are utilized as constraints in solving the inverse problem and need only be very approximate They are usually set to large positive values Experiment Settings General Signals Physical Parameters Physical Constraints Bubble Size Information Number of Sizes 100 Use Logarithmic Scale On
6. 1 Size distribution display settings IV Use default size distribution settings Max bubble size I Min bubble size EEE Cancel Figure 20 Dialog Box for Specifying Display Range of the Analyzed Results In the Cavitation Susceptibility mode only one graph Figure 21 is displayed e Filtered Received Signal Amplitude vs Applied Voltage Two vertical lines indicating the determined threshold voltage for cavitation susceptibility are also displayed The blue line is based on the minimum threshold and the green line is based on the threshold of maximum slope 36 ABS Acoustic Bubble Spectrometer USER MANUAL 7 086 v 6 0 RMS_1 ABS Acoustic Bubble Spectrometer E mx F e Edt Experiment View Help ABS Acoustic Bubble Spectrometen Beta Version 1996 2008 www dynaflovi inc com n s u a n a j u ela Cavitation Susceptibility 0 144 0 126 0 108 0 0905 0 0727 0 055 0 0373 Filtered Received Signal v 0 0195 0 0018 3 0 19 38 57 76 95 114 133 152 Applied Voltage v Py start Wr DIDIT Abs Mi ER ZO7XA Figure 21 Display of cavitation susceptibility results 4 8 Reference Signals REF After this button is highlighted the signals acquired by clicking on ES e the Acquire button are designated as reference signals see Generate Reference Data in 4 2 This button is automatically released after the acquisition is finished Also note that this bu
7. BNC connector on the ABS Interface Box marked as Transmitter to the BNC connector marked as AO IN on the terminal block of the switch using a BNC cable Connect the sending hydrophones to the BNC connects on the terminal block of the switch marked as AO 1 AO 2 in order Connect the Receiving hydrophones to the BNC connector on the Connector Box marked as Receiver 1 Receiver 2 in order Power up the programmable multiplexer switch first and then turn on the computer Turn on the amplifier switch on the BNC Connector Box Make sure the amplifier is turned on and that it has a fresh battery When not in use it should be turned off Otherwise the battery will drain Also make sure the 68 pin cable connection with the Signal Generation Data Acquisition Board is good and pushed in all the way 3 4 Setup and Cabling for a Notebook Based System The following hardware is provided as part of a notebook based ABS Acoustic Bubble Spectrometer system a a Integrated ABS Acoustic Bubble Spectrometer System Interface Box PCMCIA Expansion Cable with host card CardBus or ExpressCard type BNC Cables Optional programmable Multiplexer Switch ABS Acoustic Bubble Spectrometer USER MANUAL 7 086 v 6 0 Perform the following steps to set up the notebook based ABS Acoustic Bubble Spectrometer system hardware For the basic single set hydrophone system Figure 1 shows the setup diagram of t
8. It contains several shortcut buttons that are used to invoke different functions These shortcut buttons are listed here and described in detail below Print Preview Experiment Settings Reference Signals Acquire Analyze View Results view Signals ii B Su Continuous Mode X Stop Continuous Mode Cavitation susceptibility measurement Mode 4 2 Experiment Settings This button invokes the Experiment Settings property sheet that enables the user to input the various environmental and operating conditions for the experiment The property sheet can also be invoked from the menu by 16 ABS Acoustic Bubble Spectrometer USER MANUAL 7 086 v 6 0 clicking Experiment Settings or by pressing the F7 key There are four separate property pages as described below Screenshots of each page are shown in Figure 7 through Figure 12 a General This page has entries for title date time user s name and comments on the experiment Figure 7 Experiment Settings General Signals Physical Parameters Physical Constraints Title Date Time Wednesday January 16 208 T4510PM General User name Administrator Comment Check this bos to use the settings on this page and the following ones as default at startup Figure 5 Experimental Settings General Information Page 17 ABS Acoustic Bubble Spectrometer USER MANUAL 7 086 v 6 0 Experiment Settings General Signals
9. M n Y Radius Minirnum 10 microns Maximum 1000 microns Area of bubbles per m 3 of mixture 100000 Volume of bubbles per unit volume of mixture 100000 Cancel Figure 11 Experimental Settings Physical Constraints Page a Cavitation Susceptibility This page Figure 12 provides information for the system with the optional Cavitation Susceptibility Meter to measure the cavitation susceptibility AMPLIFICATION OF POWER AMPLIFIER specifies the amplification of the power amplifier that drives the cavitation hydrophone Please make sure that the actual amplification factor you set on the amplifier matches with the value specified To do so use constant input signal amplitude and adjust the amplification of the amplifier until the ratio of the output signal to the input signal of the amplifier reaches the 26 ABS Acoustic Bubble Spectrometer USER MANUAL 7 086 v 6 0 amplification value you require and enter the same in the ABS Cavitation Susceptibility Page MAXIMUM SIGNAL VOLTAGE gives the maximum signal voltage that will be applied to the cavitation hydrophone it should not exceed the maximum output voltage of the power amplifier for the Krohn Hite wide band power amplifier the maximum output voltage is 160 v RMS SENT SIGNAL FREQUENCY specifies the signal frequency used to test the cavitation susceptibility which usually is around 50 70 kHz and corresponds to the best response frequency range o
10. Physical Parameters Physical Constraints card info unknown sampling rate up to 5 MS s Nominal Signal Amplitude 10 Volts Number of tests perform average rm Extend data acquisition time by 1 times of default setting Test Ref ratio of power amplification of sent signal Hydrophone settings 1st set resonance freq 2nd set resonance freg 3rd set resonance freq Frequency setup Min Freq 10 kHz Max Freq 200 kHz Equal 1 frequency list start from C Linear frequency list r 96 kHz dT Correction kHz dT Correction kHz dT Correction corresponding bubble size 333 microns corresponding bubble size P H 15 8 microns Arrange frequency list automatically Number of Periods Hydrophone Distance cm Enable Signal Settings Auto Calibration V Generate Reference Data ms Frequencies up to 80 ms Frequencies up to 160 ms used forthe rest of the frequencies Number of Freq Freq Hz 10000 10100 10200 10300 10400 10600 10700 10900 11000 11100 11300 11500 11600 11800 11900 12100 Ref Gain Test Gain V Factor 1 00 1 00 1 00 1 00 1 00 Ignore Signal No No No No 1 00 1 00 1 00 1 00 1 00 1 00 1 00 1 00 1 00 1 00 1 00 1 00 1 00 1 00 1 00 1 00 Ref V Factor E Cancel Figure 6 Experimental Settings Signals Page Signals The signals property page is shown in Figure 8 The
11. The extension of the saved file is Ass Clicking on File Open enables users to open a previously saved Ass file With this feature users can view signals and results acquired previously Users can also re analyze the signals solve the inverse problem differently Export Import Clicking on File Export to export the acquired signals to individual files for each frequency in ASCII format Two types of data files are available for export the par files contain the transmitted and received signals vs time and the cpv files are used by graphic software DF CoNTOUR developed by DYNAFLOW INC which is provided with the ABS Clicking on File Export to export the experiment data to current directory at first a window pops up to let the user decide whether to export the cpv files Then a series of files are generated with names of the form xxxxnz pAr and or xxxkuz cev based on the users choice where xxx is the frequency of the signal in kHz In addition to exporting an individual file at each frequency the following files are also exported e UVF INP This file includes the sound speed ratio and the attenuation ratio at each frequency 40 ABS Acoustic Bubble Spectrometer USER MANUAL 7 086 v 6 0 Clicking on File Import to import the individual DAT files for each frequency listed in the property page Signals in the experiment settings as described in section 4 2 Note that if a corresponding DAT file does not exist for a frequen
12. V power supply to the ABS System Interface Box and turn on the power to the multiplexer b Before turning on the laptop computer make sure that the green LED lights on the chassis of the multiplexer and the ABS System Box are on c If the ABS application fails to acquire data properly close the ABS application and use the Measurement amp Automation application to ensure that the DAQ card can be detected Also use the test panel to test the DAQ card to ensure that the analog inputs and outputs are working properly d Make sure the amplifier is turned on and that it has a fresh battery When not in use it should be turned off Otherwise the battery will drain Replace battery if the low Battery LED light is on Also make sure the expansion cable connection is good on both ends and pushed all the way in 4 Operating the ABS Acoustic Bubble Spectrometer Double clicking the ABS icon stars the ABS Acoustic Bubble Spectrometer Generation II software This invokes the Graphical User Interface It includes the menu the tool bar and a plotting area The contents displayed in the plotting area depend on the operation performed they can be the transmitted and received signals either reference signals or those from an actual measurement or the analysis results 15 ABS Acoustic Bubble Spectrometer USER MANUAL 7 086 v 6 0 4 1 Tool Bar The tool bar is located just under the main frame menu at the top of the window
13. mathematics employed in the ABS Acoustic Bubble Spectrometer can be found in our JASA paper 3 2 2 Validation The complete procedure was initially tested on analytical data with varying amounts of artificial noise added It was found that to successfully recover the bubble distribution and to perform much better than previous solution techniques The bubble distributions obtained from the ABS Acoustic Bubble Spectrometer were then validated by comparison with microphotography Bubble populations were generated using electrolysis and air injection ABS Acoustic Bubble Spectrometer USER MANUAL 7 086 v 6 0 through porous tubes The bubble population obtained using the ABS Acoustic Bubble Spectrometer compared favorably with the results of microphotography Details can be found in 1 8 3 System Requirements and Setup 3 1 Hardware The ABS Acoustic Bubble Spectrometer system can operate on a PC that has Windows XP Vista 7 installed For a desktop based system one spare PCI slot is required For a notebook based system one spare PCMCIA slot CardBus or ExpressCard type is needed Sufficient hard disk space is required to store the data acquired which depends upon the parameters set by the user The basic system also utilizes two hydrophones one for transmission and one for reception of acoustic wave bursts Different sets of hydrophones can be employed with the ABS Acoustic Bubble Spectrometer as long as they have
14. one may alternately view the raw signals and the calculated results by use of the View Signals A and View Results ki buttons The experimental data including reference state data and results may be saved to disk at any time by use of File Save Based on these results refine the parameters if desired and repeat the experiment 6 Advanced Features 6 1 Utilizing the Signal Dropping Option In version 5 0 the user has the option to actively interfere with the signal processing This option should only be used by a very educated user and if not properly used could result in very erroneous results With this option the user can define criteria for dropping signal from the analysis Figure 23 shows the signal drop option page which can be activated by requesting a 42 ABS Acoustic Bubble Spectrometer USER MANUAL 7 086 v 6 0 Key from DYNAFLOW The user can choose to drop a signal if the signal to noise amplitude ratio is less than a given threshold or if the sound speed ratio from the analysis is outside of the user specified range 7 Useful Tips for Running Measurements To maintain the best signal possible make sure that the battery in the amplifier is powerful enough Also keep the hydrophone surface clean and bubble free as much as possible 8 1 Experiment Settings General Signals Physical Parameters Physical Constraints Signal Drop Options Dialog Signal Dropping Criterion IV Ratio of sig
15. ABS continuously if there is no mouse activity otherwise the Continuous Mode will be idle unless a mouse activity is detected 4 10 Stop Continuous Mode x This button is enabled when the Continuous Mode is activated Click this button to deactivate the Continuous Mode After the Continuous Mode is deactivated the button will be disabled 38 ABS Acoustic Bubble Spectrometer USER MANUAL 7 086 v 6 0 4 11 Cavitation Susceptibility Measurement Mode cav This button activates the Cavitation Susceptibility mode if the system is capable of this functionality After this button is highlighted the system is operated under Cavitation Susceptibility mode 4 11 Files and I O Important data are automatically saved to files during the experiment In both Acquire and Analyze processes the following files are generated ATTENUATION RATIO VS FREQUENCY DAT This file includes the attenuation ratio at each frequency N M3vVsRI DAT This file includes the number of bubbles at different bubble size bins N M VSRI DAT This file includes the number of bubbles per unit bin size at different bubble sizes i e number of bubbles divided by bin size NGROUPI DAT This file includes the number of bubbles the surface area of the bubbles and their contribution to the void fraction at different bubble size bins SOLN PARAMI DAT This file gives the statistics of the analysis SOUND SPEED SATIO VS FREQUENCY DAT This file includes the sou
16. Acoustic Bubble Spectromet Diar i alelan Per se OR M i 9 Ref 10 Set Scale for Signal X OK Scale for transmitted signals x 1 Cancel 2 o gt Scale for received signals P 5 I 1931 Figure 15 Dialog Box for Setting Display Scale of the Raw Signals Signal Viewing Options IX Available Number of tests View signals of an inidvidual test 1 gt M Used for average View averaged signal Cancel Figure 16 Dialog Box for Selecting Viewing Option for Multiple Tests Under the Cavitation Susceptibility mode not all signals for all voltages tested are displayed only signals at 4 selected voltages are displayed covering the typical signals with and without cavitation in the test When raw signal is displayed the Sent signal is scaled down before the amplification while the Received signal is displayed in the original scale If the Analyzed signal is displayed the graph scale is based on the analyzed Received signal which is displayed in its original scale while the Sent signal is scaled down 32 ABS Acoustic Bubble Spectrometer USER MANUAL 7 086 v 6 0 by a varying scale to fit in the graph scale determined by the analyzed Received signal debug version ABS Acoustic Bubble Spectrometer I mx F e Ed Experiment View Help ABS Acoustic Bubble Spectrometen Beta Version 1996 2008 www dynafiow inc com b u a sia w s w u s v volts
17. DYNAFLOW INC USER MANUAL 7 086 ABS VER 6 01 ABS Acoustic Bubble Spectrometer User Manual X Wu C T Hsiao G L Chahine Version 6 0 January 2011 DYNAFLOW INC 10621 J IRON BRIDGE ROAD JESSUP MD 20794 U S A Phone 301 604 3688 Fax 301 604 3689 E mail info dynaflow inc com http www dynaflow inc com ABS Acoustic Bubble Spectrometer USER MANUAL 7 086 v 6 0 Table of Contents PANS OR ACU cess iii ido a ie Elise cep Ge e e e Se K ieu Rai udi de 2 Intellectual Property and Software License Agreement 3 1 T t VO GU GU OH p ka H ERA da ie ke EME a de sed S WE nek e k k 5 2 Technical BasiS s syn seen adv tus Coal cide seco aus Ceo aen ETE 2 1 THEORETICAL FOUNDATION eee s Ki kelk 9 kake de Uk n y k dhe kUbE be dk sess ese E sese sees esee etes Eek 5 2 2 VALIDATION 55535 ciyo toy eto Kaca biv ew ya ben e 08 ku coc ote a E Pe eee Ute te Re ee eo ed 5 3 System Requirements and Setup 51 j 5 4 15 BL RENIDEVIUNTI 6 CANTON NL 6 3 3 SETUP AND CABLING FOR A DESKTOP BASED SYSTEM eee 7 3 4 SETUP AND CABLING FOR A NOTEBOOK BASED SYSTEM eee 8 4 Operating the ABS Acoustic Bubble Spectrometer 15 ZDPOOERBAR cce pee ctt ete pues EE had ees ei dia eee S
18. LM 16 4 2 EXPERIMENT SETTINGS 4 s sok Kak n kede heda e e e e n nnn nnn nnn nna n Dak ki C Ceger k n ss n a nara pa d n 16 AS ACQUIRE 5 N Dt n t Dur ied e t e t e ER n rep A ble e tee a Ras gd 28 4 4 VIEW SIGNALS eninIIeoNdr Neben e E E 29 AS A NTN Ba ADEM E E E E E UI 33 AO VIEW NEN N KAE e E E E E EE 34 4 8 REFERENCE SIGNALS nirean t Eee EE i aas 37 4 9 CONTINUOUS MODE sie tei a Va e A b vas A berd A e a Vane beka k 37 4 10 STOP CONTINUOUS MODE eese e e Ye e a a aa Pek a i e a bede kek 38 4 11 CAVITATION SUSCEPTIBILITY MEASUREMENT MODE eee eene 39 4 AA EIEES AND I Q nete esee Se We kek Se Re SNOW e b ve ye ek Se iei 39 5 Example ABS Acoustic bubble Spectrometer Experiment41 6 Advanced FeatUresS s sscesssssocessseceseseeeeeso eee d 2 6 1 UTILIZING THE SIGNAL DROPPING OPTION eeeee e keke keke ke kek k k k k k k nenne 42 7 Useful Tips for Running Measurements 43 RelfereliCes 5er A ees z e b ee 0 1 e dps sena Ve i 0e e ne ABS Acoustic Bubble Spectrometer USER MANUAL 7 086 v 6 0 Abstract This manual provides a brief description of the ABS Acoustic Bubble Spectrometer an acoustics based device that measures bubble size distributions and void fractions in liquids and measures cavitation susceptibility It explains in detail the pro
19. The software is owned by DYNAFLOW INC and is protected by United States copyright laws The Hardware and its Driver and the Software are protected Copyright Laws Patents and Trade Secrets You must treat the Software like any other copyrighted material except that you may make one copy of the Software solely for backup archival purposes You may not reverse engineer decompile or disassemble the Software and Hardware except to the extent applicable law expressly prohibits the foregoing restriction DYNAFLOW INC may have patents and or pending patent applications covering subject matters in this document The furnishing of this document does not give you any license to these patents DYNAFLOW INC grants you a non exclusive license to use one copy of the ABS Acoustic Bubble Spectrometer Software program Limited Warranty For 30 thirty days from your date of purchase DYNAFLOW INC warrants that the media on which the Software is distributed are free from defects in materials and workmanship DYNAFLOW INC will at its option refund the amount you paid for the Software or repair or replace the Software provided that a the defective Software is returned to DYNAFLOW INC or an authorized dealer within 60 days from the date of purchase and b you have completed and returned the enclosed registration Limitation of Liabilities In no event will DYNAFLOW INC be liable for any indirect special incidental economic or consequential damag
20. als of characteristics specified in the Experiment Settings Signals page are sent by the transmitting hydrophone and acquired by the receiving 28 ABS Acoustic Bubble Spectrometer USER MANUAL 7 086 v 6 0 hydrophone In order to improve the signal analysis a rectangular wave with the same duration as that of the matching sine wave is also added The Acquire function can also be invoked from the menu by clicking Experiment Acquiring Signals or by pressing the F8 key The screen is automatically refreshed after the data acquisition is completed and processed The raw or analyzed sent and received signals are displayed Figure 13 based on the user selection if set in View Signals mode originally The analysis results are displayed Figure 18 if the View Results mode is originally set For the hardware version operating under the cavitation susceptibility measurement mode a set of acoustic signals of characteristics determined in the Experiment Settings Cavitation Susceptibility page are sent by the transmitting hydrophone and acquired by the high sensitivity pressure transducer Similar as the regular ABS mode the raw or analyzed sent and received signals are displayed Figure 17 based on the user selection if set in View Signals mode originally The analysis results are displayed Figure 21 if the View Results mode is set originally 4 4 View Signals Al This button activates the View Signals mode to show the raw
21. cedures for setting up and operating the system including support for a multiple set hydrophone A step by step operation example is also provided to help the user get started ABS Acoustic Bubble Spectrometer 99 isa registered trademark of DYNAFLOW INC The ABS software is a Copyright O of DYNAFLOW INC 1995 2011 All rights reserved DYNAFLOW INC may have patents and or pending patent applications covering subject matter in this document The furnishing of this document does not convey any license to these patents Other brands or product names are trademarks 1M or registered trademarks of their respective holders No part of this document may be reproduced or transmitted in any form or by any means electronic or mechanical for any purpose without the express written permission of DYNAFLOW INC ABS Acoustic Bubble Spectrometer USER MANUAL 7 086 v 6 0 Intellectual Property and Software License Agreement This agreement governs your use of the ABS Acoustic Bubble Spectrometer product and any material enclosed with it including any manuals disks hardware PC cards and computer programs Grant of License This agreement permits you to use one copy of the product which is licensed as a single product The software is in use on a computer when it is loaded into the temporary memory i e RAM or installed into the permanent memory e g hard disk or other storage device of that computer Copyright and Restrictions
22. cy listed an error message pops up to show the information about the missing data file 5 Example ABS Acoustic bubble Spectrometer Experiment An example of taking a set of measurements with the ABS Acoustic bubble Spectrometer is provided in this section The bubble population in water at an ambient pressure of 0 kPa and a temperature of 15 C is determined The gas in the bubbles is air The following procedures are performed 1 Run the ABS Acoustic bubble Spectrometer software by double clicking on the ABS icon A screen with blank plots and a tool bar will appear If desired an existing file from a previous session with a aBs extension may be opened as a starting point Use the File Save As a utility to create a new file Select the Experiment Settings button El from the tool bar 4 Go to the General information page and fill in the information desired Figure 1 5 Go to the Signals page Edit the default frequencies to those desired Edit the default gains applied to the voltages of the transmitted and received signals by the data acquisition board such that sufficient resolution is attained for the particular configuration without saturating the received signal Figure 2 6 Select the box Generate Reference Data option to obtain the reference background data set 7 Go to the Physical Parameters page Edit the default values of these physical conditions to correspond to those of the experiment as required Fi
23. dware is provided as part of a desktop based ABS Acoustic Bubble Spectrometer system a Signal Generation Data Acquisition Board Installed in desktop computer or interface box Q External ABS Interface Box with integrated amplifier BNC Cables a Optional programmable multiplexer switch with accompanied USB cable and terminal block U Perform the following steps to set up the desktop based ABS Acoustic Bubble Spectrometer Generation II system hardware For the basic single set hydrophone system e Connect the External ABS Interface Box with the attached Signal Generation Data Acquisition Board using the 68 Pin Shielded Cable e Connect the sending hydrophone to the BNC connection on the ABS Interface Box marked as Transmitter e Connect the Receiving hydrophone to the BNC connector on the Connector Box marked as Receiver e Turn on the computer e Turn on the amplifier switch on the ABS Interface Box For the optional multiple set system e Connect the External ABS Interface Box with the attached Signal Generation Data Acquisition Board using the 68 Pin Shielded Cable ABS Acoustic Bubble Spectrometer USER MANUAL 7 086 v 6 0 Note Connect the programmable multiplexer switch to the computer using the accompanied USB cable If not attached attach the accompanying terminal block to the programmable multiplexer switch Secure the attachment by tightening the screws on the terminal block Connect the
24. e interface box and programmable switch first and then power up the laptop Select Insert Mobility Express Card and press enter option if it appears to continue booting up the computer 12 ABS Acoustic Bubble Spectrometer USER MANUAL 7 086 v 6 0 e After the system has completely booted up using the Measurement amp Automation application to check whether the programmable switch has been detected by expanding the Devices and Interfaces A device similar like NI SCXI 1127 should appear under the NI DAQmx Devices e Using the Measurement amp Automation application to check whether the DAQ card has been detected by expanding the Devices and Interfaces A device name such as PCI 6115 should appear e If the DAQ card is not detected close the Measurement amp Automation application and unplug the Express Card from the laptop e Wait for a few seconds and plug the Express Card back into the laptop e Launch the Measurement amp Automation application again the DAQ card should be detected now Click the device name to activate the device e Use test panel of the Measurement amp Automation application to test the DAQ card to ensure that the analog inputs and outputs are working properly e If the above procedures have been performed successfully turn on the amplifier switch on the BNC Connector Box the ABS system is ready for measurement For the optional multiplexer controlled multiple set hydrophone system with cavi
25. e user guess work in specifying the frequency range for each hydrophone To do so the user needs to check the check box of Automatically distribute the frequency among the hydrophones Close the signal setup page and 22 ABS Acoustic Bubble Spectrometer USER MANUAL 7 086 v 6 0 click Acquire to start the acquisition of the auto frequency distribution process which examines the frequency response characteristics of each hydrophone set and then assign the optimal frequency range to each set of hydrophones This option is presently not active AMPLIFICATION RATIO The system can be coupled with an external amplifier however usually the amplifier is needed only during the actual tests and not in the reference condition If this is the case the user needs to specify the power amplification ratio after the text Test Ref ratio of power amplification of sent signal such that the difference will be taking account for in analysis GENERATE REFERENCE DATA Also on this page is a check box Generate Reference Data which is used to indicate whether the experiment is to be conducted as a reference with a pure liquid with no bubbles The pure liquid in the same experimental configuration provides a background reference state and is used in calculating the bubble size distribution in the liquid with bubbles This reference data set is obtained by conducting an experiment where bubbles have been removed as much as possible from the liquid under co
26. es arising out of the use or inability to use the ABS Acoustic Bubble Spectrometer Product In no event will DYNAFLOW INC s liability exceed the amount paid by you for the Product Restricted Rights No part of this document may be reproduced or transmitted in any form or by any means electronic or mechanical for any purpose without the express written permission of DYNAFLOW INC Other brands or product names are trademarks or registered trademarks of their respective holders ABS Acoustic Bubble Spectrometer USER MANUAL 7 086 v 6 0 1 Introduction The ABS Acoustic Bubble Spectrometer is an acoustics based device that measures bubble size distributions and void fractions in liquids Compared to optical based devices the ABS Acoustic Bubble Spectrometer is more affordable and easier to setup and use The underlying acoustic technique is very sensitive to bubbles but practically insensitive to particulate matter unlike optical techniques that cannot readily distinguish between these The ABS Acoustic Bubble Spectrometer can be used in a wide variety of two phase flow applications where knowledge of the bubble size distribution and the volume fraction and or area of contact between the gas and the liquid are important These areas include oceanography cavitation tunnels controlled laboratory testing industrial flows and biomedical instrumentation The instrument can provide the data in near real time thus making it suitab
27. ets the duration for acquisition to be a multiple of the default acquisition time by the specified factor Experiment Settings General Signals Physical Parameters Physical Constraints Title Date Time Wednesday Januay 16 2008 v T4510PM General User name Administrator Comment Check this box to use the settings on this page and the following ones as default at startup Cancel 19 ABS Acoustic Bubble Spectrometer USER MANUAL 7 086 v 6 0 Figure 7 Experimental Settings General Information Page Experiment Settings General Signals Physical Parameters Physical Constraints card info unknown sampling rate up to 5 MS s Number of Periods Nominal Signal Amplitude 10 Volts Hydrophone Distance em Number of tests perfarm average 1 Enable Signal Settings Auto Calibration Extend data acquisition time by 1 times of default setting v Generate Reference Data Test Ref ratio of power amplification of sent signal 1 Hydrophone settings 1st set resonance freq kHz dT Correction ms Frequencies up to 80 2nd set resonance freg kHz dT Correction ms Frequencies up to 160 3rd set resonance freq kHz dT Correction ms used forthe rest of the frequencies Frequency setup Min Freq 10 kHz corresponding bubble size 333 microns Number of Freq Max Freq 200 kHz corresponding bubble size 15 8 microns Equal 1 frequency list start from 5 kH
28. f the hydrophone provided for cavitation susceptibility measurement SIGNAL CYCLES TO BE ACQUIRED specifies the number of cycles to be acquired during the data acquisition process it should be long enough to enable the detection of the cavitation events if the cavitation phenomenon exists For the signal analysis the low frequency signals should be removed from the received signal RANGE OF BLOCKED FREQUENCY specifies the range of frequency to be filtered out during the signal analysis This purpose of this filtering process is to remove background and excitation noise and keep only high frequency signals of cavitation events 27 ABS Acoustic Bubble Spectrometer USER MANUAL 7 086 v 6 0 Experiment Settings Cavitation Susceptibility General Signals Physical Parameters Physical Constraints Sent signal properties Amplification of power Maximum signal 160 Please make sure that the amplifier is set to the same amplification value as specified above Sent signal 70 kHz Signal cycles to be 100 Filtering Option Range of removed p kHz to 100 kHz Figure 12 Experimental Settings Cavitation Susceptibility Page 4 3 Acquire This button initiates acquisition of signal in the ABS hardware version and re processing of the raw signals in the ABS no hardware version if the data file loaded is a regular ABS data For the hardware version under regular ABS operation mode a set of acoustic sign
29. fferent sets of hydrophones The order of the hydrophone arrangement is in ascending frequency order e g for triple set hydrophone system the 1 set is for lower range of frequencies the 2 set is for the middle range of frequencies and the 3 set is for the higher range frequencies What the user needs to do is to specify two cut of frequencies the first frequency is specified after the text Use I set of hydrophones for the frequencies up to frequencies below this one are handled by the 1 hydrophone set The second frequency is specified after the text Use 2 1 set of hydrophones for frequencies up to Frequencies above this one are handled by the 3 set of hydrophones The system will route automatically a given frequency signal to the corresponding hydrophone according to the specification Please make sure the order of the hydrophone connections matches among the receiving and transmitting hydrophones HYDROPHONE RESPONSE CHARACTERISTICS When a system is delivered the resonance frequency and response time as specified in dT Correction of the hydrophones are given They are used for analysis for improved accuracy AUTOMATIC FREQUENCY DISTRIBUTION AMONG HYDROPHONES Except for the basic single set ABS system the user needs to specify the frequency range for each set of hydrophones Since the hydrophone performance might change at different conditions an automatic frequency distribution scheme has been implemented to remove th
30. g the Express Card back into the laptop Launch the Measurement amp Automation application again the DAQ card should be detected now Click the device name to activate the device Use test panel of the Measurement amp Automation application to test the DAQ card to ensure that the analog inputs and outputs are working properly If the above procedures have been performed successfully the ABS system is ready for measurement For the twin set hydrophone system Figure 2 shows the setup diagram of a twin set system It can drive up to two sets of hydrophones The system set up procedures are similar to the single set system except for connecting the hydrophones to the ABS System Box as described below 10 ABS Acoustic Bubble Spectrometer USER MANUAL 7 086 v 6 0 Analog output Figure 2 Set up of the twin set system e Connect the two sending hydrophones in the order of ascending resonance frequency to the Transmitter 1 and Transmitter 2 of the Integrated System Box e Connect the two receiving hydrophones in the order of ascending resonance frequency to the Receiver 1 and Receiver 2 of the Integrated System Box e Perform a similar system check to ensure the readiness of the hardware as described previously for single set hydrophone system For the optional multiplexer controlled multiple set hydrophone system Figure 3 shows the setup diagram of the multiplexer controlled triple set system A multiplexer
31. gnal to Yes Users can also manually ignore any signal that they believe is problematic by setting the value of Ignore Signal to Yes at the corresponding frequency AUTOMATIC FREQUENCY SETUP To manually set up a long frequency list can be time consuming To speed up the process the GUI can arrange the frequency automatically What the user needs to do is to specify the Min Freq minimum frequency the Max Freq maximum frequency and the Number of Freq number of frequencies and choose how to generate the frequency list Please notice that when the user changes the Min Freq and the Max Freq the corresponding bubble sizes will be automatically calculated and displayed as a guideline about the optimal 21 ABS Acoustic Bubble Spectrometer USER MANUAL 7 086 v 6 0 bubble size measurement ranges Two options are available one is to linearly arrange the frequency list with equal frequency interval choose Linear frequency list the other one is base on equal bubble size interval which corresponding to the equal 1 f interval choose Equal 1 f frequency list If the equal 1 f interval is selected the user can also specify when to start the equal 1 f interval arrangement Between the minimum frequency and this frequency equal frequency interval of 1000 Hz will be used TRIPLE SET HYDROPHONE OPTIONS If it is a multiple set hydrophone system the user can use this option to control how to distribute the frequency list among the di
32. gure 3 p 41 ABS Acoustic Bubble Spectrometer USER MANUAL 7 086 v 6 0 10 11 12 13 14 15 16 ane EN Click on the Acquire button A no bubble reference state is generated and the sent and received raw signals are displayed Similar to Figure 5 It is very useful to inspect the signals to assure that sufficient resolution was obtained and that there are no other problems such as no received signals or no delay between emitted and received signal which usually indicates electric leak problems between the transducers If these signals are not satisfactory one should return to the Signals page and modify the settings accordingly or inspect the experimental setup for problems A new reference state can then be acquired Experiments in the presence of bubbles will now be conducted having a suitable reference state in memory Select the Experiment Settings button again and go to the Signals page Turn off the Generate Reference Data option 2 e Click on the Acquire button The sent and received raw signals in the presence of bubbles are displayed Figure 5 Again it is useful to inspect these signals to assure that sufficient resolution was obtained and that there are no other problems Go to the Physical Constraints page and edit these as needed Select the Analyze button h to process the acquired experimental data The results will be displayed as in Figure 9 If desired
33. he basic single set system The analog input and output as well as the signal amplifier are integrated into the ABS System Interface Box Follow the following steps to set up the system x o 6 N of c S 2 g 9 gt T Sgnal Amplifie Analog output Figure 1 Setup of the basic single set system e Connect the Integrated System Interface Box with one end of the PCMCIA Expansion Cable and insert the other end with the PCMCIA host card into PCMCIA slot of the notebook e Connect the sending hydrophone to the BNC connector labeled as Transmitter in the Integrated System Interface Box e Connect the Receiving hydrophone to the BNC connector labeled as Receiver of the Integrated System Interface Box e Plug in the power supply and power up the interface box first then power up the laptop e Select Insert Mobility Express Card and press enter option if it appears to continue booting up the computer ABS Acoustic Bubble Spectrometer USER MANUAL 7 086 v 6 0 After the system has completely booted up using the Measurement amp Automation application to check whether the DAQ card has been detected by expanding the Devices and Interfaces on the task panel on the left of the window A device name such as PCI 6115 should appear If the DAQ card is not detected close the Measurement amp Automation application and unplug the Express Card from the laptop Wait for a few seconds and plu
34. he test signal is finished the check before Enable Signal Settings Auto Calibration will be automatically unchecked by the system and all the subsequent tests will be conducted using the setting found in the calibration process until the user checks the selection again to re conduct the calibration process The user can examine the optimized settings from the table Ref Gain and Test Gain are the gain settings for the reference and test signals respectively V Factor and Ref V Factor are the voltage factor settings for the reference and test signals respectively The actual sent signal voltage is the product of the voltage factor and the specified nominal sent signal amplitude FREQ Hz This table includes the list of selected insonification frequencies and the corresponding gains to be applied to the transmitted and received signals at each frequency The frequency list should be arranged in ascending order These should be set based on the hydrophone characteristics to attain sufficient resolution for the particular configuration without saturating the received signal Trial and error may be required The table also includes a column labeled as Ignore Signal which enables removal of any signal that is erroneous such that it will not be taken into consideration in the analysis for the bubble populations The software automatically removes any signals that give unreasonable sound speeds or bad signal to noise ratio and sets their values of Ignore Si
35. is used to route the sent signal to desired hydrophones As the basic and twin set system the analog inputs and outputs as well as the signal amplifiers are integrated into the Integrated System Interface Box Follow the following steps to set up the system A BS Acoustic Bubble Spectrometer USER MANUAL 7 086 v 6 0 How 50 kHz Hydrophone 150 kHz 250 kHz Hydrophone e gt Hydrop hone __ Laptop NES output Figure 3 Set up of the multiplexer controlled triple set system Connect the Integrated System Box with one end of the PCMCIA Expansion Cable and insert the other end with the PCMCIA host card into the PCMCIA slot of the notebook Connect the programmable multiplexer switch to the notebook using the accompanied USB cable If not attached attach the accompanying terminal block for the programmable multiplexer to the chassis of the multiplexer switch secure the attachment by tightening the screws on the terminal block Connect the BNC connector on the Integrated System Interface Box marked as Transmitter to the BNC connector marked as AO IN on the terminal block of the switch using a BNC cable Connect the sending hydrophones to the BNC connectors on the terminal block of the switch marked as AO 1 AO 2 in order Connect the Receiving hydrophones to the BNC connectors on Integrated System Box marked as Receiver 1 Receiver 2 in order Power up th
36. le for process or time varying applications The initial efforts to develop the device were funded by National Science Foundation Small Business Innovation Research SBIR awards 1 2 The device extracts the bubble population from acoustic measurements made at several frequencies It consists of a pair of hydrophones or transducers connected to a signal generation data acquisition system resident on a personal computer A data board controls signal generation by the first hydrophone and signal reception by the second hydrophone Short monochromatic bursts of sound at different frequencies are generated by the transmitting hydrophone and received by the second hydrophone after passage through the bubbly liquid These signals are processed and analyzed utilizing specialized copyrighted software algorithms developed by DYNAFLOW INC to obtain the attenuation and phase velocities of the acoustic waves and from these the bubble size distribution All the measurements and analyses can be easily and rapidly conducted through a user friendly Graphical User Interface GUI All physical experimental and analytical parameters can be modified by the user interactively Both raw and processed experimental data from experiments can be saved for future use The results are displayed graphically in real time on the screen and can also be exported or printed ABS Acoustic Bubble Spectrometer USER MANUAL 7 086 v 6 0 As an option the standard ABS Ac
37. nal to noise amplitude less than 2 v Sound speed ratio beyond the following range Minimum ratio jn lele ratios fs Figure 23 Signal dropping options References Duraiswami R and Chahine G L Bubble Density Measurement Using an Inverse Acoustic Scattering Technique NSF SBIR Phase I report also DYNAFLOW INC Technical Report 92004 1 September 1992 Duraiswami R Prabhukumar S and Chahine G L Development of an Acoustic Bubble Spectrometer ABS Using an Acoustic Scattering Technique NSF SBIR Phase II report also DYNAFLOW INC Technical Report 94001 1 July 1996 Duraiswami R Prabhukumar S and Chahine G L Bubble Counting Using an Inverse Acoustic Scattering Method J Acoustical Society of America 104 5 November 1998 Hocine C A and Ouarem M Bubble Size Measurement Study DYNAFLOW INC Technical Report 6 002 31 October 1996 Demotes Mainard F and Picard M Study of Bubble Size Measurement Technique DYNAFLOW INC Technical Report 6 002 46 September 1997 43 ABS Acoustic Bubble Spectrometer USER MANUAL 7 086 v 6 0 6 Chahine G L Duraiswami R and Frederick G S Detection of Air Bubbles in HP Ink Cartridges Using DYNAFLOW S Acoustic Bubble Spectrometer Technology DYNAFLOW INC Technical Report 97014hp 1 January 1998 7 Chahine G L Kalumuck K M Cheng J Y and Frederick G S Validation of Bubble Distribution Measureme
38. nd speed ratio at each frequency VF DAT This file includes the contributions to the void fraction at each frequency The following files are generated only in the Acquire process UVF DAT This file includes both the sound speed ratio and the attenuation ratio at each frequency The following file is generated in the Analyze process as well as View Results if it is the No Hardware version BUBBLE SIZE DISTRIBUTION DAT This file includes the number of bubbles and its contribution to the void fraction at different bubble sizes 39 ABS Acoustic Bubble Spectrometer USER MANUAL 7 086 v 6 0 In the Continuous Mode all the above files are generated for the latest run In addition void fraction and bubble size distribution information for selected runs in sequence are also generated e BUBBLE SIZE DISTRIBUTION CONT MODE DAT This file includes the number of bubbles and its contribution to the void fraction at different bubble sizes for each selected run in the Continuous Mode In addition the total void fraction and the time at which output is generated are also included e VOIDFRACTION VS TIME DAT This file includes the variation of void fraction with time for the selected runs in Continuous Mode Raw data and processed results from an experiment can be saved or reopened by two means Save Open Clicking on File Save will save all the information in a single binary file readable by the software with a name chosen by the user
39. nditions and settings otherwise identical to those to be employed in determining the desired bubble size distribution Check the box to generate this reference data set The reference data set can be saved to disk for later use or stored in memory This procedure is recommended because it frees the user from errors associated with calibration of the hydrophones in the specific configuration of the experimental setup NUMBER OF TESTS The user can specify the number of test runs n desired to obtain the averaged results by entering a number between and 20 in the Number of Tests box Sets of signals are generated and acquired as many times as specified The average of these signals is used to obtain the bubble distribution for n 1 In this case the signals of the last run are displayed see 4 4 View Signals below The sound speed ratio and attenuation vs frequency displayed are the average values see 4 6 View Results below It should be noted that this option does not work with the external trigger mode section 4 7 23 ABS Acoustic Bubble Spectrometer USER MANUAL 7 086 v 6 0 Experiment Settings General Signals Physical Parameters Physical Constraints Cavitation Susceptibility Selection of type of liquids Water Experiment Conditions Pressure 111040 Pa Temperature Gas Conditions Specific heat 14 Vapor pressure Liquid Properties Sound speed 1493 m s Density Surface Tension 00725 N m Viscosity
40. nts of the ABS Acoustic bubble Spectrometer with High Speed Video Photography CAV2001 4 International Symposium on Cavitation Pasadena CA June 2001 8 Chahine G L Kalumuck K M Development of a Near Real Time Instrument for Nuclei Measurement the ABS Acoustic bubble Spectrometer FEDSM 03 4 ASME_JSME Joint Fluid Engineering Conference Honolulu Hawaii July 2003 44
41. opped Signal This gives the user a direct indication of which signals are used during the analysis Figure 14 shows a sample screen shot of the signals that have been dropped during the signal analysis Reference abs ABS Acoustic Bubble Spectrometer He Edt Espenmert Ww Hep ABS Acoustic Bubble Spectrometer 1336 2010 www cyratow recom S e ujs a je eio atio Ad t Test uration 0 5 ms 1 39 ms Duration 0 44 ms Figure 13 Display of the Raw Sent blue and Received red Signals 30 ABS Acoustic Bubble Spectrometer USER MANUAL 7 086 v 6 0 Electrolysis 40 V AMP X10 1 abs ABS Acoustic Bubble Spectrometer 1 He Ede Expenmert ew Heb n s u e n w Test Figure 14 Dropped signals during the analysis are crossed out in signal display window If the Number of Tests specified in the Signals property page Figure 9 is greater than 1 another dialog box Figure 16 appears to enable the user to specify the option to view the signals of an individual test or to view the averaged signals of the tests The user can select a test of interest by clicking the selection buttons If the check box Used for average is checked that individual test will be used for signal averaging otherwise that specific test will be excluded from the signal average process 31 ABS Acoustic Bubble Spectrometer USER MANUAL 7 086 v 6 0 test 2 video b abs ABS
42. or analyzed sent and received signals most recently acquired Figure 13 When clicked on while the Ctr key is pressured a dialog box appears Figure 15 to let the user specify the scale or magnification factors to be applied to the vertical axes of the signals for display This enables zooming in on signal details that may be too small to see well with normal magnification Another way to view the sent received signals or reference signals is by selecting the Test Signals or Reference Signals under either Original Signals or Analyzed Signals type on the View pull down menu If it is the Original Signals type the acquired raw signal is displayed If it is the Analyzed Signals type the processed signals will be displayed The following descriptions apply to regular ABS mode As shown in Figure 13 the corresponding responses to sinusoidal and rectangular wave are displayed side by side The duration of the rectangular wave is also output on top of the signal Also on the upper left corner of the 29 ABS Acoustic Bubble Spectrometer USER MANUAL 7 086 v 6 0 display window either Ref or Test is marked to indicate that the signal displayed is the reference signal or test signal Another feature in the signal display window of Version 5 0 is that the signals that have been dropped e g small signal to noise ratio from bubble distribution calculations during the signal analysis process are crossed out and marked as Dr
43. oustic Bubble Spectrometer can be upgraded and used to determine the liquid susceptibility to cavitation In order to do so a hydrophone projects acoustic power in the liquid with an increasing intensity A sensitive transducer measures the resulting pressure field The signals of this transducer are then analyzed and any high frequency emission from cavitation bubble is detected Cavitation is called when a threshold of the rms of the emitted signals is crossed 2 Technical Basis 2 1 Theoretical Foundation Bubble size distribution measurements using the ABS Acoustic Bubble Spectrometer are based on a dispersion relation for sound wave propagation through a bubbly liquid A multiphase fluid model for sound propagation through bubbly liquids is combined with a model for the bubble oscillations including various damping modes The combined model relates the attenuation and phase velocity of a sound wave to the bubble population or size distribution These relations produce two Fredholm integral equations of the first kind that are ill posed and require special treatment for solution particularly in the presence of noise Novel algorithms developed by DYNAFLOW 1 3 are able to accurately solve these equations using a constrained optimization technique that imposes a number of physical constraints on the solution This renders the equations well posed and the solution more accurate A detailed presentation of the underlying physics and
44. suitable performance characteristics over the frequency and distance ranges of the application and their characteristics are known and specified to the system For an ABS Acoustic Bubble Spectrometer system with optional multiple set hydrophone support multiple pairs of hydrophones with different resonance frequencies can be connected to the system at the same time to enhance the performance through coverage of a larger frequency band and to expand the available measurement range For the upgraded system with the capability to measure cavitation susceptibility a low frequency emitting hydrophone and a high sensitivity receiving transducer for cavitation detection are also provided 3 2 Software The ABS Acoustic Bubble Spectrometer software runs on a Windows XP Vista 7 operating system or above It enables the user to conduct the measurements and analyses through a user friendly Graphical User Interface GUI from which the user can easily input the control and operating ABS Acoustic Bubble Spectrometer USER MANUAL 7 086 v 6 0 parameters for the experiment specify analysis options and view analysis results The detailed steps required for control of the various boards data acquisition signal analysis inverse problem solution and data output are thus transparent to the user The various options and tasks are accessed through a series of menus and dialog boxes 3 3 Setup and Cabling for a Desktop Based System The following har
45. tation susceptibility measurement CSM Figure 4 shows the set up sketch of a multiplexer controlled triple set system with optional cavitation susceptibility meter Compared to the regular triple set system this system has an extra hydrophone to generate cavitation and an extra high sensitivity pressure transducer to detect the cavitation events As other systems all the analog inputs and outputs and the signal amplifiers for the regular ABS receiving hydrophones are integrated into the ABS System Interface Box The pressure transducer has its dedicated unit for power supply and signal amplification The signals from the pressure transducer and the 1 receiving ABS hydrophone share the same analog input channel as shown in Figure 4 These two signals are sent to the multiplexer and then are routed to the analog input based on operation mode The set up procedures are similar to the multiplexer controlled triple set system except that the 13 ABS Acoustic Bubble Spectrometer USER MANUAL 7 086 v 6 0 cable connections are a little more involved follow the procedures as described below Pressure transducer P E Be 150 kHz Hydrophone Flow Cav Hydro Analog output j Figure 4 System setup of the multiplexer controller triple set system with cavitation susceptibility measurement e Connect the BNC connector on the ABS System Box marked as Transmitter to the BNC connector marked as AO IN on
46. the terminal block of the switch using a BNC cable e Connect the sending hydrophones to the BNC connectors on the terminal block of the switch marked as AO 1 AO 2 in order Make sure the hydrophones are connected in ascending order of the resonance frequency e Connect the cavitation hydrophones to the BNC connector on the terminal block of the switch marked as Cav AO e Connect the Receiving hydrophones to the BNC connectors on Integrated System Interface Box marked as Receiver 1 Receiver 2 in order matched with the sending hydrophones e Connect the pressure transducer to the BNC input connector of the standalone power supply signal conditioner unit for the pressure transducer Connect the output connector of the power supply signal 14 ABS Acoustic Bubble Spectrometer USER MANUAL 7 086 v 6 0 conditioner unit and the BNC connector on the terminal block marked as Rec 2 e Connect the BNC connector marked as To Multiplexer on the Integrated System Interface Box to the BNC connector marked as Rey I on the terminal block e Connect the BNC connector marked as AJ on the terminal block to the BNC connector marked as From Multiplexer on the Integrated System Interface Box e Perform similar system check to ensure the readiness of the hardware as described previously for triple set hydrophone system Notes d Insert the PCMCIA host card into the notebook computer plug in the 12
47. tton has to be clicked to release the Cavitation Susceptibility mode if it is activated 4 9 Continuous Mode Q In some cases it may be desirable to monitor the bubble characteristics continuously Click this button to activate the Continuous Mode which runs the ABS continuously Before activating the Continuous Mode the user needs to make sure that the reference data are available A dialog window Figure 22 appears after the button is clicked to allow the user to set up the Continuous Mode The Time delay between sequences 37 ABS Acoustic Bubble Spectrometer USER MANUAL 7 086 v 6 0 specifies the time delay before one sequence of emission reception and the next The Output options allow the user to choose whether the analyzed results are written to a file If No output is selected the results of the sequences are not output to files however results for the most current one can be displayed on the screen If Output results is selected the results of the sequences are written to files at the desired frequency see 4 10 for detail While the Continuous Mode is activated the button will be disabled until the Continuous Mode is deactivated Continue Mode Options Time delay between sequences 0 s Dutput options Mo output C Qutput results p Cancel Figure 22 Dialog Box for setting up the Continuous Mode One restriction to the Continuous Mode is that the cursor has to be left on top of the button to run the
48. umber of bubbles within the measuring volume this must be multiplied by the size of the measuring volume in cubic centimeters After the View Results kd button is clicked while the Ctrl key is pressed down a dialog box Figure 19 appears to enable the user to select the display option for viewing the analyzed results If the Use Previous Default Display Settings button is clicked the default ranges or the ranges used in the previous display are used for displaying the analyzed results If the Specify Results Display Settings button is clicked a new dialog window Figure 20 appears to let the user specify the desired ranges for sound speed ratio attenuation ratio and bubble size distribution In addition the user can also select to display the attenuation ratio in either power spectrum or RMS form The user can also show the analysis results of the experiment by clicking on Analyzed Results in the menu item View RESULT DISPLAY oP X Specify Results Display Settings Use Previous Default Display Settings Figure 19 Dialog Box for Selecting Display Option of the Analyzed Results 35 ABS Acoustic Bubble Spectrometer USER MANUAL 7 086 v 6 0 Display Settings Sound speed ratio display settings Use default sound speed settings Max sound speed ratio 163 45 Min sound speed ratio 163 45 Attenuation display settings Use default attenuation settings Use RMS ratio Max attentuation 2 Min attenuation ratio
49. user can specify the number of periods and the nominal peak signal amplitudes in volts maximum signal amplitude is 0 volts of the sent signals for test and reference signals respectively enter the distance between the two hydrophones in the experiment and build a table that lists signal properties Note The burst duration for each transmitted signal is then equal to the ratio of the number of periods to the signal frequency 18 ABS Acoustic Bubble Spectrometer USER MANUAL 7 086 v 6 0 HARDWARE INFORMATION The DAQ card information and its maximum sampling rate is automatically detected and used by the system Information such as PCI 6115 DAQ card used sampling rate up to 10 MS s will be displayed the system will automatically determine the sampling rate to use based on the signal characteristics under consideration DATA ACQUISITION DURATION EXTENSION FACTOR The default time duration for data acquisition is set to be four times the time of flight between hydrophones in the liquid This equals the hydrophone distance divided by the sound speed in pure liquid plus the duration of emission This default setting is good in normal cases If this default duration is not optimal for the particular experiment e g the duration is too short to obtain the complete response signal the user can adjust the time duration by changing the value of N of the user input in Extend data acquisition time by N times of default setting which s
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