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FDS+Evac – Technical Reference + User's Guide

1. Note that EVACUATION FALSE should be given for MB vents or otherwise these vent are introduce also to the evacuation geometry amp VENT MB YMIN SURF_ID OPEN EVACUATION FALSE amp VENT MB YMAX SURF_ID OPEN EVACUATION FALSE Evacuation geometry input Fire geometry holes should be duplicated if they are also wanted to show up in the evacuation geometry amp HOLE XB 0 21 0 01 4 39 5 61 0 00 2 00 EVACUATION TRUE amp HOLE XB 9 99 10 21 4 39 5 61 0 00 2 00 EVACUATION TRUE 44 amp HOLE XB 0 21 0 01 7 39 8 61 2 60 4 60 EVACUATION TRUE amp HOLE XB 9 99 10 21 2 39 3 61 2 60 4 60 EVACUATION TRUE A fan boundary condition is used to calculate the evacuation flow fields amp SURF ID OUTFLOW VEL 0 00001 TAU_V 0 1 Define the evacuation vents for the main evacuation meshes there should be an evacuation vent at every place where humans can go inside some door exit etc object This vent is not at an outer boundary of the domain nor at a solid object thus there should be an OBST behind it Left Exit lst Floor amp VENT XB 0 20 0 20 4 40 5 60 0 40 1 60 SURF_ID OUTFLOW MESH_ID MainEvacGrid EVACUATION TRUE RGB 0 0 255 amp OBST XB 0 40 0 20 4 40 5 60 0 40 1 60 EVACUATION TRUE RGB 30 150 20 This vent is at the outer boundary of the domain i e it is on a soli
2. study the flow of humans through a narrow door and through a wide door and the other geometry was used to study human flows in a corridor using densities 1 0 and 2 0 persons per square metre There were 100 humans randomly located at the 5 x 5 m square in the door flow calculations Corridor flow calculations had 96 or 192 humans inside the corridor depending on the density Thousand egress simulation with different random initial human properties were performed for each of these four different cases In total eleven model parameters A Bi i v9 Fis A Prinses we T and whose values were varied 20 using uniform distributions The monitored output quantity was the specific human flow in all cases and the Spearman s rank correlation coefficients RCC were calculated for these four cases and they are shown in Fig 6 20 Door 1 0m Door 2 0m Corr 2 0m Flow 1 m s 1500 2000 A N 2500 3000 Flow 1 m s gt Door 1 0m Door 2 0 m Corr 2 0m 0 04 0 06 0 08 B m 0 10 0 12 Flow 1 m s Door 1 0m Door 2 0m Corr 2 0m Door 1 0m Door 2 0m Corr 2 0m Door 1 0m Door 2 0m Corr 2 0m Door 1 0m Door 2 0m Corr 2 0m Flow 1 m s Flow 1 m s Flow 1 m s eta 0 7 0 9 1 1 1 3 1 5 1 7 0 3 0 5 0 7 0 9 111 1 3 vo S t s 0 00 0 0
3. DET_MEAN 10 0 DET_LOW 5 00 DET_HIGH 15 0 PERS ID Elderly FYI Elderly diameter and velocity DEFAULT_PROPERTIES Elderly PRE_EVAC_DIST 1 PRE_MEAN 10 0 PRE_LOW 5 0 PRE_HIGH 15 0 DET_EVAC_DIST 1 DET_MEAN 10 0 DET_LOW 5 00 DET_HIGH 15 0 Initial positions of the humans These humans will go to the left exit if it is not blocked by smoke amp EVAC ID HumanLeftDoorKnown NUMBER_INITIAL PERSONS 25 XB 1 0 9 0 1 0 9 0 0 4 1 6 QUANTITY BLUE KNOWN_DOOR_NAMES LeftExit KNOWN_DOOR_PROBS 1 0 PERS_ID Male These humans will go to the right exit if it is not blocked by smoke amp EVAC ID HumanRightDoorKnown NUMBER_INITIAL PERSONS 25 XB 1 0 9 0 1 0 9 0 0 4 1 6 QUANTITY RED K K w NOWN_DOOR_NAME S RightExit NOWN_DOOR_PROBS Te 03 PERS_ID Female These humans know both doors so they will use the nearest visible known door which is not blocked by smoke amp EVAC ID HumanBothDoorsKnown NUMBER_INITIAL_PERSONS 25 XB 1 40 9 0 1 079 0 0 4 1 6 QUANTITY GREEN KNOWN_DOOR_NAMES LeftExit RightExit KNOWN_DOOR_PROBS 1 0 1 0 PERS_ID Child These humans do not have a known door and they will try to go to the nearest visible exit door amp EVAC ID HumanNoDoorKnown NUMBER_INITIAL PERSONS 25 XB 1 0 9 0 1 0 9 0 0 4 1 6 QUANTITY BLACK P
4. PLASTER FYI Quintiere Fire Behavior CONDUCTIVITY 0 48 SPECIFIC_HEAT 0 84 DENSITY 1440 amp SURF ID WALL RGB 200 200 200 MATL_ID GYPSUM PLASTER THICKNESS 0 012 amp PART ID smoke MASSLESS TRUE SAMPLING_FACTOR 1 Ordinary fire calculation geometry input amp OBST XB 0 20 10 20 0 20 10 20 2 40 2 60 floor amp HOLE XB 2 20 7 80 2 20 7 80 2 39 2 61 floor hole amp OBST XB 2 00 8 00 2 00 2 20 2 60 3 60 balustrade amp OBST XB 2 00 8 00 7 80 8 00 2 60 3 60 balustrade amp OBST XB 2 00 2 20 2 00 8 00 2 60 3 60 balustrade amp OBST XB 7 80 8 00 2 00 8 00 2 60 3 60 balustrade amp OBST XB 10 20 11 60 4 20 5 80 2 40 2 60 floor amp OBST XB 0 20 0 00 0 20 10 20 0 00 5 00 amp OBST XB 10 00 10 20 0 20 10 20 0 00 5 00 amp OBST XB 0 20 10 20 0 20 0 00 0 00 5 00 amp OBST XB 0 20 10 20 10 00 10 20 0 00 5 00 amp OBST XB 10 00 11 60 4 20 4 40 0 00 2 40 Right Corridor Wall amp OBST XB 10 00 11 60 5 60 5 80 0 00 2 40 Right Corridor Wall amp HOLE XB 0 21 0 01 4 39 5 61 0 00 2 00 Left Door amp HOLE XB 9 99 10 21 4 39 5 61 0 00 2 00 Right Door Hole The fire as an burner amp OBST XB 3 00 4 00 3 00 4 00 0 00 0 60 SURF_ID INERT amp VENT XB 3 00 4 00 3 00 4 00 0 60 0 60 SURF_ID BURNER EVACUATION FALSE
5. The corridor case has a constant human density Thus these two parameters can not have an effect through the density Larger social force i e larger A and or B will make a forward walking person to reduce his her speed in order not to step on someone s heels when the anisotropy parameter As is less than unity Increasing the walking velocity will of course increase the specific flow Decreasing 7 i e increasing the motive force to go forward increases specific flows quite 21 rapidly for the door geometry This effect is not as pronounced in the corridor case because there is no free space in front of humans to accelerate and also the humans are already moving with some velocity whereas they are almost standing and waiting their turn in front of the door The anisotropy parameter of the social force A controls how eager humans are to push those who are in front of them When A is large then humans are pushy The effect of the wall force parameter B is to modify the effective width of doors and corridors thus increasing its value will make the effective width smaller and this will decrease human flows slightly 5 4 Summary One should be very careful when constructing the geometry where humans are moving One should use Smokeview to see the human flow fields before making a full evacuation simulation The effect of the parameters in the human movement algorithm Eqs 1 9 are understood well and user should usually not u
6. and the effect of CO is only due to the hyperventilation i e it is assumed that the CO is such low that it does not have narcotic effects Carbon dioxide does not have toxic effects at consentrations of up to 5 percent but it stimulates breathing which increases the rate at which the other fire products are taken up The fraction of an incapacitating dose of CO is calculated as FEDco 4 607 1077 Coo t 12 where t is time in seconds and Cco is the CO concentration ppm The fraction of an incapacitating dose of O is calculated as t FEDo 0 60 exp 8 13 0 54 20 9 Co 13 15 Table 2 Preference order used in the exit selection algorithm The last two rows have no preference This 1s because the evacuees are unaware of the exits that are unfamiliar and invisible and thus can not select these exits preference visible familiar disturbing conditions 1 yes yes no 2 no yes no 3 yes no no 4 yes yes yes 5 no yes yes 6 yes no yes No preference no no no No preference no no yes where t is time in seconds and Co is the Oz concentration percent The carbondioxide induced hyperven tilation factor is calculated as exp 0 1930 Cco 2 0004 7 1 i HVco 14 where Cco is the CO concentration percent Human is considered to be incapacitated when the FED value exceeds unity An incapacitated human 1s modelled as an agent who does not e
7. are chosen by keywords DIAMETER_DIST VELOCITY_ DIST TAU_EVAC_DIST DET_EVAC_DIST and PRE_EVAC_DIST where the choices for the statistical distributions are listed on Table The most used ones are 0 no dis tribution x_MEAN is used 1 uniform distribution x_LOW and x_HIGH are used 2 normal distribution x_MEAN is the mean x_PARA is the std dev x_LOW and x_HIGH are the cut offs i e the values are within the interval x_LOW x_HIGH If x_LOW is not given gt x_LOW 0 0 If x_HIGH is not given then x_HIGH is a very large number Above x refers to one of the strings DIA VEL TAU DET or PRE DET_MEAN DET_PARA DET_PARA2 DET_LOW DET_HIGH detection time parameters of the distri bution PRE_MEAN PRE_PARA PRE_PARA2 PRE_LOW PRE_HIGH reaction time parameters of the distri bution is equal to pre evacuation time if no detection time is given VEL_MEAN VEL_PARA VEL_PARA2 VEL_LOW VEL_HIGH The target walking speed v9 parameters of the distribution see Eq DIA MEAN DIA PARA DIA PARA2 DIA LOW DIA HIGH Diameter of human circle 2Rq param eters of the distribution see Table 1 and Fig 1 TAU_MEAN TAU_PARA TAU_PARA2 TAU_LOW TAU_HIGH relaxation time 7 parameters of the dis tribution see Eq FCONST_A FCONST_B L_NON_SP Social force parameters A B A see Eq C_YOUNG KAPPA Contact force parameters k and k see Eq D_TORSO_MEAN D_SHOULDER_MEAN The mean diameters of the
8. because the FDS Evac is not deternimistic model After the runs examine the results calculate averages variances etc Getting Help Error Statements Bug Reports Send bug reports to Timo Korhonenevtt fi The subject line should start with the characters FDS Evac Bug Send help requests to Timo Korhonentvtt fi The subject line should start with the characters FDS Evac Help If the run stops early and the error message ERROR Initialize_Humans Evac line Mesh 1_human is printed on stderr then the initialization of humans failed i e FDS Evac was not able to put the humans on the areas specified in the input file Check that you are not trying to put too many humans on a too small area See the positions of those humans that FDS Evac was able to generate by using Smokeview Note that in some runs with the exactly input file you might get the error message and in some other runs not The reason for this is that FDS Evac uses random numbers to generate the properties of humans and their initial positions 25 8 Setting up the Input File for FDS Evac This section is a short manual to the FDS Evac program Read first the FDS manual because here only those features and keywords are presented which differ from the ordinary FDS fire input The optional keywords are presented with a slanted typewriter font like KAPPA and the normal keywords with upright typewriter font like XB One can use the optional keywords to
9. corridors are reproduced nicely by the underlaying dynamics Congestion can be studied The effect of the many input parameters of the human movement model are understood well and their effect on the human flows is known The shortcomings of FDS Evac are Geometry and the calculational mesh i e rectanglular objects whose edges are along the x and y are the main elements used to construct the geometry including inclines and stairs Merging flows in stairs are not easy to model No elevators 50 e Evacuation calculations can only be done by the serial version of the FDS5 executable e Visualization of the evacuation objects like exits door etc on the Smokeview window e The user input is not easy to give i e no support for importing CAD drawings etc Users should notice that the evacuation part of FDS5 is under development and the features and user input may change in the future 51 References 1 2 Ly 3 La 4 5 6 7 8 a 9 10 11 12 13 14 15 Korhonen T Hostikka S and Keski Rahkonen O A Proposal for the Goals and New Techniques of Modelling Pedestrian Evacuation in Fires Proceedings of the 8th International Symposium on Fire Safety Science International Association for Fire Safety Science pp 557 567 2005 Korhonen T Hostikka S Heli vaara S Ehtamo H Matikainen K Integration of an Agent Based Evacuati
10. flow field meshes for this case besides the fire mesh amp HEAD CHID evac_examplel TITLE Room Evacuation Test Fire mesh es amp MESH IJK 60 54 12 XB 0 4 11 6 0 4 10 4 0 0 2 4 One floor with 2 exit doors thus we need one main evac mesh EVACUATION TRUE EVAC_HUMANS TRUE two door flow meshes EVACUATION TRUE EVAC_HUMANS FALSE Main evacuation mesh for this floor This mesh contains the humans Evacuation meshes should all have an unique ID string defined amp MESH IJK 60 54 1 XB 0 4 11 6 0 4 10 4 0 4 1 6 EVACUATION TRUE EVAC_HUMANS TRUE ID MainEvacGrid Additional door flow fields Note main evacuation mesh and the door flow meshes should have same XB and IJK amp MESH IJK 60 54 1 XB 0 4 11 6 0 4 10 4 0 4 1 6 EVACUATION TRUE ID LeftExitGrid amp MESH IJK 60 54 1 XB 0 4 11 6 0 4 10 4 0 4 1 6 EVACUATION TRUE ID RightExitGrid 37 amp TIME TWFIN 200 0 amp MISC SURF_DEFAULT WALL amp DUMP NFRAMES 200 DT_PART 0 5 DT_HRR 1 0 DT_SLCF 1 0 DT_PL3D 10 0 DT_ISOF 10 0 amp REAC ID POLYURETHANE FYI C_6 3 H_7 1 NO 2 1 NFPA Handbook Babrauskas SOOT_YIELD 0 10 N 1 0 6 3 H 7 1 O 2 1 amp SURF ID BURNER HRRPUA 1000 PART_ID smoke COLOR RASPBERRY amp MATL ID GYPSUM PLASTER FYI Quintiere
11. good for congested situations when three circles are used 14 to describe a human body These parameters were modified such that the interaction strength parameter A was made velocity dependent A v 2000 Max 0 5 0 0 N For the contact force parameters values k 12x 104 kg m k 4x10 kgsm and cy 500 kg s are used both for the human human and for the human wall interactions The mass of a default male is mi 80 kg and his moment of inertia was chosen to be If 4 0 kg m For other humans the mass and the moment of inertia are obtained by scaling For the relaxation angular time parameter 7 a value of 0 2 s is used The angular velocity parameter w has a value of 47 s i e two rounds per second in FDS Evac In principle all the above parameters may be dependent on the person in question But in FDS Evac only the body sizes walking velocities and the motive force parameter 7 are personalised by choosing them from a random distribution A uniform distribution ranging from 0 8 s to 1 2 s is used for 7 and the used uniform distributions for the body dimensions and for the walking speeds are shown in Table 1 3 3 Fire and Human Interaction By using FDS as the platform of the evacuation calculation we have direct and easy access to all local fire related properties like gas temperature smoke and gas densities and radiation levels Fire influences evacuation conditions it may incapacitate humans and in extreme case
12. is INERT You could specify some other solid material for the default surface material but FDS Evac uses only the color information EVAC_PRESSURE_ITERATIONS is the number of Poisson solver iterations at each human flow field time step If you human flow fields do not look nice you might need to increase this Too large number makes the human flow field calculation to take too much CPU time Default is 50 EVAC_TIME_ITERATIONS is the number of human flow field calculation time steps One should have a nice converged human flow field so some iterations are needed Too large number means too long CPU time Default is 50 28 The flow fields which are used to guide humans out of the building or to some other targets are cal culated before the actual fire and evacuation simulation i e flow field calculation has t lt 0 The product tfow EVAC_TIME_ITERATIONS x EVAC_DT_FLOWFIELD defines the duration of the evacuation flow field calculation The fields should become steady state during this time Note that the ramp up time of the boundary conditions TAU_V 0 1 given on the SURF ID OUTFLOW line should be well below the duration of the flow field calculation tgo Default tao is 50 x 0 01 s 0 5 s 8 5 The VENT Namelist Group Because one needs to specify special VENTs for the evacuation calculation the VENT namelist group has an additional logical item EVACUATION If itis TRUE then this VENT is omitted in the fire c
13. it as is and then make the appropriate changes to the input file for the desired scenario By running a sample case the user will become familiar with the procedure learn how to examine the results and ensure that his her computer is up to the task before embarking on learning how to create new input files The FDS Evac executable is a single CPU executable of the FDS fds5 exe Assuming that an input file called CHID fds exists in some directory the user must run the program in a DOS command shell as follows Open up a Command Prompt window and change directories to where the input file for the case is then run the code by typing fds5 exe CHID fds to begin a run which will output some text on the Command Prompt window If the user wants to save the text output going on the Command Prompt window she he should type fds5 exe CHID fds 2 amp gt 1 gt CHID err to begin a run 7 1 Updating an Existing FDS Input File to a FDS Evac Input File e Make a FDS fire input file for your project and do the fire smoke spread calculations using the single CPU version of the FDS executable Note that the present version of the evacuation module demands that the fire part can be run using the serial version of FDS If the memory requirements of your fire calculation demand the use of the MPI version of FDS then you can not couple the evacuation calcu lation with the fire calculation 1 e you can not use smoke and gas consentrations in the evacuati
14. of the FDS5 Thus the running of FDS Evac evacuation simulation is done similarly as an ordinayry FDSS fire simulation see the FDS User s Guide 4 for details FDS Evac uses also Smokeview 5 to visualize the results and also the computer hardware requirements are similar with FDS Note that for now FDS Evac can only be run on a single processor mode i e one can not use multiple processors Work is in progress to enable the calculation of the smoke and toxic gas consentration using multiple processors so that these can be later read in when doing a single processor evacuation calculation The evacuation module FDS Evac is embedded in the FDS Version 5 which could be obtained from the URL http www fds smv net Download the latest version of FDS Smokeview and install it The resulting FDS single processor executable is also the executable of the evacuation calculation module The homepage of FDS Evac is http www vtt fi fdsevac and this page contains the combined Technical Reference and User s Guide of FDS Evac and some exam ples on the use of FDS Evac This web site is also used to store the validations and verification test cases including the input files 1 2 Special Features FDS Evac is under construction For now it is best suited to do calculations of buildings whose floors are horizontal Sports halls with spectator stands or concert halls can also be modeled It is also assumed that the different levels of the bui
15. pak I ct T al 7 an 5 mn z T sp aTe Figure 5 Test geometries used to calculate the specific flows through doors and corridors NNNNA NNNUNN SASSY __ VeececccccecccccccecegliL SSS inna SSS SN TOVUUOOUOUUTEOOUOTOOUTEOOUEOOOU TET OOOO OUTONO OTOA SS p D q KEKE OTT TTT WZZZZLLLLA RSS kha rm S Door 0 8 m Door 2 0 m W Corr 2 0 m2 E Corr 1 0 m2 Door 0 8 m Door 2 0 m M Corr 2 0 m2 E Corr 1 0 m2 ES TTT N N TTT 0 4 0 2 00 0 2 RCC 04 06 08 1 0 0 20 0 15 0 10 0 05 RCC 0 00 Figure 6 Rank correlation coefficients RCC for specific flows through doors and corridors Widths 0 8 m and 2 0 m were used for doors and human densities 1 0 m and 2 0 m were used for corridors 5 3 Human Parameter Sensitivity The human movement algorithm of FDS Evac has many parameters Some of these are related to the physical description of humans like the body size the mass the walking speed and the moment of inertia The others are the parameters of the chosen movement model 7 T7 w the parameters of the social force A B A and the parameters of the contact force k K cg To test the relative importance of these parameters Monte Carlo simulations were performed to find the parameters which have the greatest effect on human flows Two different geometries were used in the simulations see Fig 5 One of the geometries was used to
16. var EA 4 Testing and Verification Aa Jntroducton aia Si be oR Bo Be Bose Heke he Sot peut So we ee ed 4 2 Component Testing s as m A ee oe ae eke ea oe A ea et ai a 43 Qualitative Verification 2 ee 4 4 Numerical Les ca A A aa a ag ean ea a GP ae iaa han cd 5 Model Sensitivity 5 1 Introduction gt secca 42a a eg E eR ee Qe a ae ad ne 3 22 Grid Sensitivity poe do toe Soho Be a ee ee ea Re eh oes ee ea 5 3 Human Parameter Sensitivity 2 2 aaa ee SAS SUMMA Oi eee Sas aude Ae ae ae BSE Aa aon od A ay E E Sone ae NEA 6 Model Validation and Verification Ol JIntrod ction s leeis rd ta a ay ae th aed aE ee dite iA 6 2 Comparisons with Test Data aoaaa ee 6 3 Comparisons with Engineering Correlations 0 0000 0000 4 6 4 Comparisons with Other Evacuation Models oo o 02 eee 7 Running FDS Evac 7 1 Updating an Existing FDS Input File to a FDS Evac Input File 7 2 Getting Help Error Statements Bug Reports o o 8 Setting up the Input File for FDS Evac 8 1 The Numerical Evacuation Meshes ee 8 2 The TIME Namelist Group 8 3 The SURF Namelist Group 12 12 12 15 16 17 17 18 18 18 19 19 19 19 19 20 22 22 22 22 22 22 23 23 25 8 4 8 5 8 6 8 7 8 8 8 9 8 10 8 11 8 12 8 13 8 14 8 15 The MISC Namelist Group The VENT Namelist Group The OBST Namelist Group The HOLE Namelist Group The PERS Nam
17. 1 60 11 60 4 40 5 60 0 40 1 60 amp VENT XB 11 60 11 60 4 40 5 60 0 40 1 60 SURF_ID OUTFLOW MESH_ID RightExitGrid EVACUATION TRUE Right Exit Fan Next is just a counter amp EXIT ID RightCounter IOR 1 FYI Comment line COUNT_ONLY TRUE XB 10 00 10 00 4 40 5 60 0 40 1 60 Evacuation calculation human properties Note Parameters DENS_INIT and COLOR_METHOD affect all humans and the values read in from the last amp PERS line where they exits are used for all humans amp PERS ID Adult FYI Male Female diameter and velocity DEFAULT_PROPERTIES Adult PRE_EVAC_DIST 1 PRE_MEAN 10 0 PRE_LOW 5 0 PRE_HIGH 15 0 DET_EVAC_DIST 1 DET_MEAN 10 0 DET_LOW 5 00 DET_HIGH 15 0 DENS_INIT 4 0 COLOR_METHOD 7 amp PERS ID Male FYI Male diameter and velocity DEFAULT_PROPERTIES Male PRE_EVAC_DIST 1 PRE_MEAN 10 0 PRE_LOW 5 0 PRE_HIGH 15 0 DET_EVAC_DIST 1 DET_MEAN 10 0 DET_LOW 5 00 DET_HIGH 15 0 amp PERS ID Female FYI Female diameter and velocity DEFAULT_PROPERTIES Female PRE_EVAC_DIST 1 PRE_MEAN 10 0 PRE_LOW 5 0 PRE_HIGH 15 0 DET_EVAC_DIST 1 DET_MEAN 10 0 DET_LOW 5 00 DET_HIGH 15 0 amp PERS ID Child FYI Child diameter and velocity DEFAULT_PROPERTIES Child PRE_EVAC_DIST 1 PRE_MEAN 10 0 PRE_LOW 5 0 PRE_HIGH 15 0 DET_EVAC_DIST 1 40
18. 2 0 04 Bw m 0 06 0 08 Figure 7 Effects of different model parameters A Bi i vo 7 and B on the specific flows through doors and corridors The corridor has 2 0 m human density and two doors widths 1 0 m and 2 0 m are used It is seen from Fig 6 that the parameters A Bi Aj vw Ti and Bu have the largest impact on the specific flows through doors and corridors Thus further simulations were done to quantify these effects Each of these six parameters were varied separately and 100 simulations were done for each discretely chosen value of the parameters Two different door widths 1 0 m and 2 0 m were chosen to represent a narrow and a wide door Corridor flow was calculated using a density of 2 0 persons per square metre because it is known that around this density the specific flow has its maximum value The results of these in total almost 20000 simulations are shown in Fig 7 where the markers represent the average of 100 simulations and standard deviation is shown as error bars Note that in FDS Evac the initial properties and positions of humans are not deterministic because the humans are randomly positioned the parameters Rg vo and 7 are sampled from a random distribution and there are small random forces in Eqs 1 and 5 Increasing the values of A and B increases the social force which tries to keep humans apart from each other and thus the specific flow for door geometry will decrease
19. 50 XB 11 60 11 60 4 40 5 60 0 40 1 60 amp VENT XB 11 60 11 60 4 40 5 60 0 40 1 60 SURF_ID OUTFLOW MESH_ID RightExitGrid EVACUATION TRUE Right Exit Fan Next is just a counter amp EXIT ID RightCounter IOR 1 FYI Comment line COUNT_ONLY TRUE XB 10 00 10 00 4 40 5 60 0 40 1 60 Second floor doors etc This is a combination of a door leading to a stairs which is leading directly to outside of the building DOOR gt CORR gt EXIT combination amp DOOR ID LeftDoor2nd IOR 1 FYI Comment line VENT_FFIELD LeftDoorGrid2 TO_NODE LeftCorr XYZ 0 0 8 00 3 6 XB 0 20 0 20 7 40 8 60 3 0 4 2 amp VENT XB 0 20 0 20 7 40 8 60 3 0 4 2 SURF_ID OUTFLOW MESH_ID LeftDoorGrid2 EVACUATION TRUE Left Door Fan 2nd amp CORR ID LeftCorr FYI Comments MAX_HUMANS_INSIDE 20 EFF_LENGTH 8 5 FAC_SPEED 0 7 TO_NODE LeftCorrExit amp EXIT ID LeftCorrExit FYI A dummy exit the end point to a corridor object IOR 1 XB 0 40 0 40 7 40 8 60 0 40 1 60 This is a combination of a door leading to a stairs which is leading to the first floor DOOR gt CORR gt ENTR combination amp DOOR ID RightDoor2nd IOR 1 FYI Comment line VENT_FFIELD RightDoorGrid2 TO_NODE RightCorr 46 XYZ 10 0 3 00 3 6 XB 10 20 10 20 2 2 i 40 3 60 3 0 4 2 40 3 60 3 0 4 2 SURF_ID OUTFLO
20. ERS_ID Adult 41 Figure 10 Example 2 Evacuation calculation geometry An evacuation hole e g do not put humans on top of the fire amp EVHO ID Evho_Fire FYI Do not put humans close to the fire XB 2 0 5 0 2 0 5 0 0 4 1 6 Fire calculation output amp BNDF QUANTITY WALL TEMPERATURE amp SLCF PBX 2 40 QUANTITY TEMPERATURE Evacuation output used to plot the evacuation flow fields amp SLCF PBZ 1 500 QUANTITY VELOCITY VECTOR TRUE amp TAIL The second input file specifies a two floor building see Fig 10 each floor consisting of one human movement area 1 e only one main evacuation mesh per floor is needed There is a fire in downstairs and the smoke is going to the second floor by an opening at the ceiling The second floor is connected to the first floor in the egress calculation i e the second floor humans are transfered to the first floor by the combination of doors and stairs The second floor has two exit doors one leading to the stairs going to the first floor the right exit and one leading to the stairs leading directly to outside of the building the left exit The first floor has two exit doors 42 SHEAD CHID evac_example2 TITLE 2 Floor Evacuation Test Fire mesh es amp MESH IJK 54 50 25 XB 0 2 10 6 0 0 10 0 0 0 5 0 Main evacuation meshes for the floors These meshes contains the humans Evacua
21. Fire Behavior CONDUCTIVITY 0 48 SPECIFIC_HEAT 0 84 DENSITY 1440 amp SURF ID WALL RGB 200 200 200 MATL_ID GYPSUM PLASTER THICKNESS 0 012 amp PART ID smoke MASSLESS TRUE SAMPLING_FACTOR 1 Ordinary fire calculation geometry input amp OBST XB 0 20 0 00 0 20 10 20 0 00 2 40 amp OBST XB 10 00 10 20 0 20 10 20 0 00 2 40 amp OBST XB 0 20 10 20 0 20 0 00 0 00 2 40 amp OBST XB 0 20 10 20 10 00 10 20 0 00 2 40 amp OBST XB 10 00 11 60 4 20 4 40 0 00 2 40 amp OBST XB 10 00 11 60 5 60 5 80 0 00 2 40 amp HOLE XB 0 21 0 01 4 39 5 61 0 00 2 00 amp HOLE XB 9 99 10 21 4 39 5 61 0 00 2 00 The fire as a burner amp OBST XB 3 00 4 00 3 00 4 00 0 00 0 60 SURF_ID INERT amp VENT XB 3 00 4 00 3 00 4 00 0 60 0 60 SURF_ID BURNER 38 EVACUATION FALSE Note that EVACUATION FALSE should be given for MB vents or otherwise these vent are introduce also to the evacuation geometry amp VENT MB YMIN SURF_ID OPEN EVACUATION FALSE amp VENT MB YMAX SURF_ID OPEN EVACUATION FALSE Evacuation geometry input Fire geometry holes should be duplicated if they are also wanted to show up in the evacuation geometry amp HOLE XB 0 21 0 01 4 39 5 61 0 00 2 00 EVACUATION TRUE amp HOLE XB 9 99 10 21 4 39 5 61 0 00 2 00 EVACUATION TRUE A fa
22. N_DOOR_NAMES LeftExit RightExit OWN_DOOR_PROBS 1 0 1 0 RS_ID Child 48 These humans do not have a known door and they will try to go to the nearest visible exit door amp EVAC ID HumanNoDoorKnown NUMBER_INITIAL PERSONS 25 XB 1 07905 09 0 0d db QUANTITY BLACK PERS_ID Adult 2nd Floor All of these humans know the right door on the 2nd floor and the right exit on the first floor On the average only 50 1 know the left door on the second floor and none knows the left exit on the first floor amp EVAC ID Human2ndFloor NUMBER_INITIAL PERSONS 50 XB 0 5 9 5 0 5 9 3 3 0 4 2 QUANTITY MAGENTA KNOWN_DOOR_NAMES LeftDoor2nd RightDoor2nd RightExit KNOWN_DOOR_PROBS 0 5 1 0 1 0 PERS_ID Adult An evacuation hole e g do not put humans on top of the fire amp EVHO ID Evho_Fire FYI Do not put humans close to the fire XB 2 0 5 0 2 0 5 0 0 4 1 6 An evacuation hole e g do not put humans on top of the opening in the ceiling amp EVHO ID Evho_2ndFloor FYI atrium space XB 2 0 8 0 2 0 8 0 3 0 4 2 Fire calculation output amp BNDF QUANTITY WALL TEMPERATURE amp SLCF PBX 2 40 QUANTITY TEMPERATURE Evacuation output used to plot the evacuation flow fields amp SLCF PBZ 1 000 QUANTITY VELOCITY VECTOR TRUE amp SLCF PBZ 3 600 QUANTITY VELOCITY VECTOR TRUE am
23. Stress Model for People Facing a Fire Journal of Environmental Psychology 13 137 147 1993 20 Fang Z Lo S M and Lu J A On the Relationship between Crowd Density and Movement Veloc ity Fire Safety Journal 38 271 283 2003 21 IMO Interim guidelines for evacuation analyses for new and existing passenger ships MSC Circ 1033 International Maritime Organization London 6 June 2002 22 Vattulainen L 53 Acknowledgements The Evacuation Module of the Fire Dynamics Simulator has been under development for four years Dr Kevin McGrattan of NIST is acknowledged for the help during the implementation of the evacuation sub routine in the FDS code and Dr Glenn Forney of NIST is acknowledged for the modifications needed in the visualization program Smokeview University of Helsinki and Helsinki University of Technology are acknowledged for the co operation The development work of FDS Evac has been funded by the VTT Technical Research Centre of Fin land the Finnish Funding Agency for Technology and Innovation the Finnish Fire Protection Fund the Ministry of the Environment and the Academy of Finland The Building and Fire Research Laboratory at NIST is acknowledged for the hospitality during the visits of one of the authors T K 54
24. T_HIGH 15 0 47 amp PERS ID FY DE PR PR DE DE amp PERS ID Child I Child diameter and velocity FAULT_PROPERTIES Child E_EVAC_DIST 1 E_MEAN 10 0 PRE_LOW 5 0 PRE_HIGH 15 0 T_EVAC_DIST 1 T_MEAN 10 0 DET_LOW 5 00 DET_HIGH 15 0 FY DE PR PR DE DE Initial Elderly I Elderly diameter and velocity FAULT_PROPERTIES Elderly E_EVAC_DIST 1 E_MEAN 10 0 PRE_LOW 5 0 PRE_HIGH 15 0 T_EVAC_DIST 1 T_MEAN 10 0 DET_LOW 5 00 DET_HIGH 15 0 positions of the humans lst Flo These h amp EVAC ID NU XB QU KN KN PE These h amp EVAC ID NU XB QU KN KN PE These h known d amp EVAC ID NU XB QU KN KN PE or umans will go to the left exit if it is not blocked by smoke HumanLeftDoorKnown MBER_INITIAL PERSONS 25 11079405 LEx07 9 0 004 Le ANTITY BLUE OWN_DOOR_NAMES OWN_DOOR_PROBS RS_ID Male LeftExit 1 0 umans will go to the right exit if it is not blocked by smoke HumanRightDoorKnown MBER_INITIAL_ PERSONS 25 1 09 07 105 920 064 1 06 ANTITY RED OWN_DOOR_NAMES RightExit OWN_DOOR_PROBS 1 0 RS_ID Female umans know both doors so they will use the nearest visible oor which is not blocked by smoke HumanBothDoorsKnown MBER_INITIAL_ PERSONS 25 1 07 9 032 170 920 O ANTITY GREEN OW
25. The tests suggested by IMO do not include any quantitative verification because IMO sees that At this stage of development there is insufficient reliable experimental data to allow a through quantitative verification of egress models Until such data becomes available the first three components of the verification process component testing functional verification qualitative verification are considered sufficient 4 4 Numerical Tests 1 CORR and walking speed CORR and EVSS stairs with many different ways 5 Model Sensitivity 5 1 Introduction This section concentrates on the effects of different input parameters on the outputs Especially the flows through doors corridors and stairs are examined because these are usually the main bottlenecs of an evac uation of a building This section does not address the point if the chosen algorithms numerical methods etc are appropriate for the evacuation simulation or not Only the sensivity of the chosen algorithms and numerical methods are examined and reported 5 2 Grid Sensitivity In principle the algorithm described in Sec 3 does not have any underlaying grid It is continuous in time and place But the implementation of the method in FDS Evac introduces computational grids These grids are used to define the geometry of the calculation The most obvious grid sensivity issue is that the resolution for the obstructions like doors stairs etc is the grid resolution The other subt
26. VTT Technical Research Centre of Finland FDS Evac Technical Reference User s Guide FDS 5_RC6 Evac 1 10 Timo Korhonen and Simo Hostikka VTT Technical Research Centre of Finland P O Box 1000 FI 02044 VTT Finland August 6 2007 Disclaimer VTT Technical Research Centre of Finland makes no warranty expressed or implied to users of FDS Evac and accepts no responsibility for its use The mention of computer hardware or commercial software does not constitute endorsement by VTT Technical Research Centre of Finland nor does it indicate that the products are necessarily those best suited for the intended purpose Contents 1 Introduction 1 Getting Started 2 4 8 5 a A ae he a A a cra Mids oe 1 2 Special Features eisian Ge ew ale Gl hk Sk Al Oh alee Gia Gf alee Greta 2 Model Documentation 2 1 Name and Version of the Model 0 ce ee 2 2 Typeof the Model ooo e Da a Se ee ee ee 2 3 Model Developers 2 2 a n i a aa a O ee 2 4 Relevant Publications 2 5 Input Data Required to Run the Model o e e 220 Model Results A Mw oh Se 2 E ew ohh Be Sa ee a 2 7 Uses and Limitations 2 a a 3 1 Introduction a oia a ee 3 2 Human Movement Mode 3 3 Fire and Human Interaction O AN eo A A fe S lh hw gh Se Sad be 32d MGTOUPS ia hee Perea A AGP elas ay ae bola a one de a ats Mae ee baw ted 3 6 Numerical Method doc a Seeks ALAR ae Bear Bh Sy wee le ae
27. W amp VENT XB 10 20 10 20 MESH_ID RightDoorGrid2 EVACUATION TRUE CORR ID RightCorr FYI Comments MAX_HUMANS_INSIDE 20 EFF_LENGTH 8 5 FAC_SPEED 0 7 TO_NODE RightEntry amp ENTR ID RightEntry FYI Comments IOR 1 XB 10 20 10 20 1 00 2 20 0 40 1 60 amp HOLE XB 9 99 10 20 1 00 2 20 0 40 1 60 EVACUATION TRUE RGB 30 150 20 1st Floor Entry amp OBST XB 10 20 10 40 1 00 2 20 0 40 1 60 EVACUATION TRUE RGB 30 150 20 1st Floor Entry Evacuation calculation human properties Note amp PERS amp PERS amp PERS Parameters DENS_INIT and COLOR_METHOD affect all humans and the values read in from the last amp PERS line where they exits are used for all humans ID Adult FYI Male Female diameter and velocity DEFAULT_PROPERTIES Adult PRE_EVAC_DIST 1 PRE_MEAN 10 0 PRE_LOW 5 0 PRE_HIGH 15 0 DET_EVAC_DIST 1 DET_MEAN 10 0 DET_LOW 5 00 DET_HIGH 15 0 DENS_INIT 4 0 COLOR_METHOD Ors ID Male FYI Male diameter and velocity DEFAULT_PROPERTIES Male PRE_EVAC_DIST 1 PRE_MEAN 10 0 PRE_LOW 5 0 PRE_HIGH 15 0 DET_EVAC_DIST 1 DET_MEAN 10 0 DET_LOW 5 00 DET_HIGH 15 0 ID Female FYI Female diameter and velocity DEFAULT_PROPERTIES Female PRE_EVAC_DIST 1 PRE_MEAN 10 0 PRE_LOW 5 0 PRE_HIGH 15 0 DET_EVAC_DIST 1 DET_MEAN 10 0 DET_LOW 5 00 DE
28. ad in if there are no fire meshes EVACUATION FALSE spec ified in the input If there is at least one fire mesh specified and also at least one main evacuation mesh EVAC_HUMANS TRUE and EVACUATION TRUE specified then this file is re calculated and saved on the disk Note that both files CHID_evac eff and CHID_evac fed are assuming that the evacuation meshes and geometry are exactly the same in the new calculation than was in the one which wrote the files 10 FDS Evac Output Files FDS Evac produces a file CHID_evac csv which has information on the number of humans on the different floors and stairs at a given time as well as the total number of humans inside the building The file also list the number of humans gone through each exit and door The first column is the time and the second column is the number of humans inside the whole building Then the number of humans in each main evacuation meshes floors and in each corridor stairs CORR namelists are given After these the number of humans gone through various exits and doors are reported The last three columns are printed only if the FED is used i e the smoke and toxic gas information is available The first of these columns reports the number of dead humans i e those whose FED values are larger than unity The next column is the maximum value of FED among all humans dead or alive Note that the FED value of the dead humans will continue to build up as if
29. alculation The default value is FALSE The keyword MESH_ID should also be given if the VENT is not needed in all evacuation flow field calculations on this floor Note that an evacuation VENT without MESH_ID is put on every evacuation flow field on this floor This means that it is better always to have the item MESH_ID specified if EVACUATION TRUE is given Note that in FDS5 VENT must always be defined on a solid surface or on the outer boundary of the computational domain Thus the user may need to place additional evacuation OBSTs behind the VENTs used to generate the evacuation flow fields 8 6 The OBST Namelist Group One may need to specify special OBSTs for the evacuation calculation which are not present in the fire calculation Thus the OBST namelist group has an additional logical item EVACUATION If itis TRUE then this OBST is omitted in the fire calculation If the evacuation flow fields need different obstacles for different human flow fields then the item MESH_ID should be given for the evacuation obstacles Usually these additional evacuation obstacles are introduced at places where humans are not allowed to walk 8 7 The HOLE Namelist Group This is similar to the OBST namelist group Only difference is that the HOLE lines of the fire calculation should have a keyword EVACUATION FALSE set and these lines should be duplicated to the evacuation geometry having EVACUATION TRUE set If the evacuation flow fields need dif
30. arameters required by the evacuation part of FDS Evac to describe a particular scenario are conveyed via one text file which is the same that is used for FDS created by the user For the fire driven fluid flow related parameters see the FDS documentation The input file of FDS Evac is such that it can be used without any modifications to run an ordinary FDS calculation i e FDS is neglecting all evacuation related parameters which are present in the input file A complete description of the input parameters required by the evacuation module of FDS Evac can be found in the FDS Evac User s Guide part of this document 2 6 Model Results FDS Evac computes the position the velocity and the dose of toxic gases of each human inside the com putational domain at each discrete time step The movement of humans can be visualized after simulation using the Smokeview program The number of humans gone through different parts of the evacuation sce nario as well as the number of humans in different nodes are saved in simple comma delimeted text file that can be plotted using a spreadsheet program Some additional quite detailed information are written to the diagnostic standard error channel which could be redirected to the hard disk 2 7 Uses and Limitations Although FDS Evac can address many egress scenarios there are limitations in all of its algorithms Some of the more prominent limitations of the model are listed here Geometry The efficie
31. by adding an additional force that points to the centre of the group This force is called as the group force The magnitude of the group force describes how eagerly the group members try to keep the group together It can be given different values for different kinds of groups For example a group consisting of a mother and a child should have a larger group force than a group of work mates The group model is not yet available in FDS5 but it will be added to later versions of the program The model has been programmed to a test version and the results are promising but quantitative effects of the model are yet to be analysed The results of these analyses will be presented in a separate paper 3 6 Numerical Method The translational and rotational equations of motion are solved using a modified velocity Verlet algorithm where the translational motive force part is solved using a self consistent dissipative velocity Verlet algo rithm 22 and the other parts are solved using the standard velocity Verlet algorithm which can be found in any basic textbooks on molecular dynamics simulations The time step used in the algortihm is adjusted during the simulations by the maximum forces excerted on humans The time step varies between 0 0xx1 and 0 0xxx1 seconds Exit door algorithm The estimated evacuation time is approximated in the present version of FDS Evac simply by dividing the distance to the door by the unimpeded walking velocity of the person T
32. d also have an outflow boundary at the top exit speed DP defined in Eq 9 is larger when the body angle differs much from the desired movement direction Langston et al 10 used a different formula for the motive torque which had a form of a spring force During this work it was noticed that a force like that will make humans to rotate around their axis like harmonic oscillators and thus some angular velocity dependent torque should be used In FDS Evac method humans are guided to exit doors by the preferred walking direction vector field v and this field is obtained using the flow solver of the FDS This vector field is obtained as an approxi mate solution to a potential flow problem of a two dimensional incompressible fluid to the given boundary conditions where all walls are inert and the chosen exit door acts as a fan which extracts fluid out of the domain This method or rather a trick produces a nice directional field for egress towards the chosen exit door see Fig 4 A field of this kind will always guide humans to the chosen exit door This route will not be the shortest one but usually it is quite close to it This field will guide more humans to the wider escape routes than on the narrower ones due to the fact that the field is a solution to an incompressible flow Note that in the present version of FDS Evac escaping agents have a rule for the exit door selection Thus the above sentence applies when there are many ro
33. d object thus no need for an OBST behind it Right Exit lst Floor amp VENT XB 11 60 11 60 4 40 5 60 0 40 1 60 SURF_ID OUTFLOW MESH_ID MainEvacGrid EVACUATION TRUE RGB 0 0 255 This vent is not at an outer boundary of the domain nor at a solid object thus there should be an OBST behind it Right Exit 2nd Floor amp VENT XB 10 20 10 20 2 40 3 60 3 0 4 2 SURF_ID OUTFLOW MESH _ID MainEvacGrid2 EVACUATION TRUE RGB 0 0 255 amp OBST XB 10 20 10 40 2 40 3 60 3 0 4 2 EVACUATION TRUE RGB 30 150 20 Right Door 2nd This vent is not at an outer boundary of the domain nor at a solid object thus there should be an OBST behind it Left Exit 2nd Floor amp VENT XB 0 20 0 20 7 40 8 60 3 0 4 2 SURF_ID OUTFLOW MESH _ID MainEvacGrid2 EVACUATION TRUE RGB 0 0 255 amp OBST XB 0 40 0 20 7 40 8 60 3 0 4 2 EVACUATION TRUE RGB 30 150 20 Left Door 2nd An exit namelist defines an exit door which takes humans out of the calculation SEXIT ID LeftExit IOR 1 FYI Comment line VENT_FFIELD LeftExitGrid XYZ 0 20 5 00 1 50 45 XB 0 20 0 20 4 40 5 60 0 40 1 60 amp VENT XB 0 20 0 20 4 40 5 60 0 40 1 60 SURF_ID OUTFLOW MESH_ID LeftExitGrid EVACUATION TRUE Left Exit Fan amp EXIT ID RightExit IOR 1 FYI Comment line VENT_FFIELD RightExitGrid XYZ 9 80 5 00 1
34. e Because the obstacles are put in the mesh but the exits or doors are not be sure that exits are wide enough Use Smokeview and activate mesh lines It does not matter if the end points of the exits or doors are somewhat inside solid obstacles For now FDS Evac has limitations on the number of humans which can be in the same main evacuation mesh The program stops and writes out an error message if more than 10000 humans are tried to put to the same evacuation mesh Usually one main evacuation mesh extends over a whole floor of the building There may be many main evacuation meshes e g different floors of the building in the FDS Evac calculation and the total number of humans is not restricted by the program the only limit is the available computer memory The user should know that if there is more than a couple of thousands humans on an evacuation floor then the calculation is going to be CPU expensive FDS Evac enables coupled fire and evacuation simulations The evacuation part uses smoke and gas consentrations from the fire calculation to affect the movement and decision making of the evacuating hu mans In principle the coupling could be made also to the other direction i e humans are influencing the fire calculation e g by opening doors but this feature is not yet implemented in FDS Evac Concentrations of O2 CO and CO are used to calculate Purser s Fractional Effective Dose FED concept 16 which is used to incapasita
35. e this is a crude approximation but fast to compute 4 Testing and Verification 4 1 Introduction An archive of the verification tests of FDS Evac are on the FDS Evac web pages These verification tests include the ones suggested in the IMO Interim paper 21 and some other component and numerical tests This manual contains only a short summary of these test and it might not be up to date so more interested reader should visit the web pages to get the most recent information 4 2 Component Testing IMO and other component tests 1 IMO 1 Maintaining set walking speed in corridor 2 IMO 2 Maintaining set walking speed up staircase 3 IMO 3 Maintaining set walking speed down staircase 4 IMO 4 Exit flor rate 5 IMO 5 Response time 6 IMO 6 Rounding corners 7 IMO 7 Assignment of population demographics parameters 8 Smoke vs momement speed tests 1 4 7 1 m extinction coeff 9 FED tests CO CO CO2 O2 For the functional verification required by IMO a good technical documentation should be enough The manual should set out in a comprehensible manner the complete range of model capabilities and inherent assumptions and give a guide to the correct use of the capabilities 18 4 3 Qualitative Verification IMO and other qualitative tests 1 IMO 8 Counterflow two rooms connected via a corridor 2 IMO 9 Exit flow cowd dissipation from a large public room 3 IMO 10 Exit route allocation 4 IMO 11 Staircase
36. elist Group The EVAC Namelist Group The EVHO Namelist Group The EXIT Namelist Group The ENTR Namelist Group The DOOR Namelist Group The CORR Namelist Group The EVSS Namelist Group 9 Additional FDS Evac Input Files 10 FDS Evac Output Files 11 Sample Calculation 12 Conclusion References Acknowledgements 36 36 37 50 52 54 1 Introduction This document describes how one does an egress calculation by using the Fire Dynamics Simulator FDS 3 4 developed at National Institute of Standards and Technology NIST and the evacuation module 1 2 developed at VTT Technical Research Centre of Finland This combined fire and evacuation simulation pro gram is called as FDS Evac in this document The basic algorithm behind the egress movement is to follow each person by an equation motion i e do some kind of an artificial molecular dynamics for humans The forces acting on humans are both physical forces like contact forces and gravity and psycholigical forces exerted by the environment and other humans This approach allows each person to have its own personal properties and escape strategies i e persons are treated as autonomous agents The model behind the movement algorithm is the social force model introduced by Helbing 6 7 8 9 and the modification of the model to a better description of a human body by Langston et al 10 Humans are modeled as ellipses moving in a 2D geometry Actually the ell
37. ferent holes for different fields then the item MESH_ID should be given for the evacuation calculation holes Holes are treated in the FDS input a little bit different than the obstacles i e first all obstacles are read in and after this the holes are created This is true for all meshes so the evacuation meshes can mix holes and obstacles incorrectly if there are no EVACUATION FALSE on the fire calculation holes If you have an ordinary FDS5 input file and want to use this as a starting point of a FDS Evac input file you should add EVACUATION FALSE keyword to every HOLE line which you have in the FDS5 fire input After this you should duplicate these hole lines and change the kewyword EVACUATION value to TRUE if you want the same holes to appear correctly in the evacuation geometry 8 8 The PERS Namelist Group This namelist group is used to define human types There are five default human types defined and they are Adult Male Female Child and Elderly see Table 1 for their properties DEFAULT_PROPERTIES Adult Male Female Child or Elderly If not given default values are used see the end of Sec 3 2 Note that these values are overridden if they are explicitly given in the PERS namelist input line 29 Properties like human diameter walking speed pre evacuation time and force constants are given here Some of the values might be given as distributions The distribution types
38. fines a door Similar to EXIT but the humans are not removed from the calculation The humans are put to some other part of the calculation e g to a stairs to a different room etc ID ID string of the door One can refer to this door by its name XB coordinates should be a line in the x y plane the z should belong to a main evacuation mesh IOR direction of the door e g 1 humans are going z direction 2 humans are going y direction direction means room door some other place VENT_FFIELD The ID string of the evacuation flow field behind this exit door The humans are guided to this exit door by the specified flow field FLOW_FIELD_ID Used if this door is a target for some other evacuation element and there are no known doors nor visible ones available If no FLOW_FIELD_ID is given then the main evacuation mesh flow field of this floor is used XYZ Co ordinates which are used in the exit door selection algorithm to decide if the door is visible or not Default is the mid point of XB KEEP_XY saves the information on the position of the person relative to the width of the door i e if the target of this door is DOOR or ENTR then human is placed according to this information TO_NODE Where humans are going when going inside this door TO_NODE can be DOOR EXIT CORR or ENTR EVAC_MESH If there are overlapping main evacuation meshes then this parameter could be used to specify the mesh where this DOOR line is app
39. he distance to a door is calculated along a bee line both for the visible and non visible doors The distance should 17 be calculated along the exit path and also an estimated queueing time at the door should be added to the estimated evacuation time but this is not yet implemented in the model The smoke density calculated by the FDS5 fire simulation can be used to detect a fire By default smoke density is not used for detection User gives as inputs a detection time distribution and a reaction time distribution for the evacuating humans If smoke is used to detect fire then user should give the detection threshold concentration mg m A human detects a fire when the smoke concentration reaches its threshold value at the position of the human or if the user given detection time has been reached The smoke or toxic gas concentrations affect the exit door selection algorithm By default toxic gas concentrations are used CO CO2 O2 FED effect door is no smoke if FED time dist vO less than 0 000001 A door is usable and visible as long as FED less than unity If smoke concentration is used then user gives the threshold visibility value for a door to be no smoke A door is usable i e visible as long as visibility is 0 5 distance to the door Visibility 3 extinction coeff If there is no line of sight to the door local concentrations at the human position are used and the distance to the door is calculated along a bee lin
40. he smoke transport and the prediction of Oz levels it does much worse on the prediction of the CO concentration In the standard mixture fraction model of FDS the amount of CO produced is decided by the user input Exit Route Selection The exit door algorithm is still a relatively simple one It does not include any kind social interactions like herding behavior The user has also more or less full control on the doors which different human groups will be using In some applications this can be listed as a benefit of the model but this leaves too much trust on the user s expertise and or intentions Detection and Reaction Times The pre movement time of the evacuating humans is decided by the user input by giving distributions for the detection and reaction times In addition to the detection time given user input the local smoke consentration can be used to trigger the detection 10 Applications There is no model for elevators in the current version of the FDS Evac Nor there is any specific objects relevant to maritime applications Concert halls and sport facilities may be difficult to model due to the limitations dictated by the rectangular computational mesh 11 Figure 3 Definitions of the human dimensions and the radial vectors R and R 3 Theoretical Basis for the Evacuation Model 3 1 Introduction As said the method of Helbing s group is used as the starting point of the human movement algorithm of FDS E
41. humans in the evacuation meshes i e the initial positions of the humans ID ID string of the group of humans XB where the humans are put z should belong to a main evac mesh NUMBER_INITIAL_PERSONS how many persons are put in the area XB ANGLE By default the orientation of humans is random but by giving angle 0 360 one can specify the orientation of persons Angle O means that humans are facing towards 2 QUANTITY Color of the squares in Smokeview Note that if a person is dead it is colored as YELLOW PERS_ID From which person class the properties are generated randomly If no PERS_ TD is given then the default values are used FLOW_FIELD_ID Flow field in the room floor which this person is initially following 1 e specifies to which door a person tries to go if no known nor visible door is available KNOWN_DOOR_NAMES The ID strings of the known exit doors KNOWN_DOOR_PROBS The probabilities that the exit doors are known At the initialization phase the known doors for persons are drawn using these probabilities Default values are equal to ones EVAC_MESH If there are overlapping main evacuation meshes then this parameter could be used to specify the mesh where this EVAC line is applied NOTE If no PERS_ 1D is given on EVAC lines then the default values are used for the properties of persons These default values are given inside the code and they might be changing during the development of the code So o
42. impeded speed of a human downwards the plane is v FAC_VO_DOWN x vo FAC_VO_HORI The unimpeded speed of a human horisontally along the plane is v FAC_ VO_HORI x vo 34 ESC_SPEED The speed of an escalator One can use EVSS as a simple model of an escalator humans are all moving with the velocity ESC_SPEED along the escalator 1 e they are not overtaking each others or walking on the escalator 35 9 Additional FDS Evac Input Files The FDS Evac calculation might have also other input files than the CHID fds file These files are not needed but they may be used to speed up the calculation and also to separate the fire and evacuation parts of the calculation The file CHID_evac eff contains the converged human flow fields which are calculated at the begin ning of the FDS Evac calculation If this file exist and there are no fire meshes EVACUATION FALSE it is read in Otherwise it is re calculated and saved on the disk This file is useful if one is doing many human egress calculations using exactly the same geometry but with different human input e g varying the number of humans the democraphics of humans etc It is very useful when doing Monte Carlo calculations in a quite complex buildings One do not need every time to calculate the human flow fields and thus one is saving some CPU seconds The file CHID_evac fed contains the smoke and gas concentration information from the FDSS5 fire calculation This file is tried to re
43. ined 26 Figure 8 A 2D evacuation mesh e Check your EVAC lines that you are not trying to put too many humans on a too small area Typical human diameter is somewhere between 0 5 0 6 m so you can not put more than about four person per a square meter If you are trying to populate the floor more densly the program will stop after the initialization phase Note that the initial position of humans are random so different runs with the same input file may or may not stop for this reason if the initial human density is close to the critical value Use the Smokeview to see the initial positions of those humans who were positioned succesfully and see the output on stderr to see the position of the human which could not be placed correctly at the initialization 8 1 The Numerical Evacuation Meshes The fire and evacuation meshes are separate ones One can do only a fire calculation only an evacuation cal culation or both at the same time The calculation mode is chosen by activating the meshes or deactivating them i e commenting the corresponding amp MESH lines out Evacuation mesh lines have a keyword EVACUATION TRUE on the amp MESH line The default is FALSE i e the fire meshes do not need the keyword EVACUATION This is true also more generally 1 e one can always run a fire simulation using the fds5 exe executable even if there exists evacuation input in the input file The FDSS fire calculation ignores all evacua
44. iptical shape of the human body is approximated by three overlapping circles see Fig 1 just like in the Simulex program 11 13 14 15 and in the MASSEgress program 12 The body dimensions and the unimpeded moving speeds of typical human population types are shown in Table 1 The body diameters and walking speeds are drawn randomly for each generated human from uniform distributions whose widths are also given in the table The body diameter and moving speed distributions are taken to be same as in the Simulex program 11 13 14 15 for the Male Female Child and Elderly categories The category Adult is just a simple superposition of the Male and Female categories Table 1 Unimpeded walking velocities and body dimensions in FDS Evac The offset of shoulder circles is given by ds Ra Rs for the definition of the other body size variables Ra Rs Rs see Fig 1 Body type Ra R i Ra Rs Ra ds Ra Speed m m s Adult 0 255 0 035 0 5882 0 3725 0 6275 1 25 0 30 Male 0 270 0 020 0 5926 0 3704 0 6296 1 35 0 20 Female 0 240 0 020 0 5833 0 3750 0 6250 1 15 0 20 Child 0 210 0 015 0 5714 0 3333 0 6667 0 90 0 30 Elderly 0 250 0 020 0 6000 0 3600 0 6400 0 80 0 30 Figure 1 The shape of the human body is approximated by a combination of three overlapping circles Shown are also the definitions of the body size variables 1 1 Getting Started The evacuation method developed at VTT is implemented as subrutines
45. j K dij rij Avi tij 4 where Avi is the difference of the tangential velocities of the circles in contact Av is the difference of their normal velocities and vector t is the unit tangential vector of the contacting circles This force applies only when the circles are in contact i e dj rj gt 0 Note that Eq 4 contains also a physical damping force 10 with a damping parameter cg which the original model by Helbing ef al does not have This parameter reflects the fact that the collision of two humans is not an elastic one The physical wall human interaction f is treated similarly and same force constants are used The term fav can be used to describe attraction or repulsion between humans like a herding behaviour or an adult children interaction It could also be used to form pairs of humans e g describing a fire fighter pair entering the building All of the force terms in Eq 2 are relatively short ranged and they need a line of sight connection Longer ranged forces could be taken in to account by changing the preferred walking velocity field v Equations 1 4 describe the translational degrees of freedom of the evacuating humans The rotational degrees of freedom are treated similarly i e each human has his her own rotational equation of motion z d Pi t Li dt MO n t 5 where t is the angle of the human at time t 7 is the moment of inertia n7 t is a small random fluc
46. lding are separated from each other i e they are connected to each other by stairs escalators doors and similar objects Wide stairs or inclines can also be used to connect different floors but this is not as straigthforward as to use the default stairscase model There are no merging flows allowed in the default staircase model so FDS Evac is not yet easy to use for tall buildings The staircase algorithm is still very simple and it should not be trusted too much if the stairs get crowded At this point this is not a problem because there are no merging flows in the corridor stairs i e the exit door at the floor restricts the flow to the corridor quite efficiently If merging flows are needed to simulate staircases then the detailed geometry of the staircase could be modeled but this is not usually very practical way of doing things The evacuation calculation needs in addition to the fire calculation meshes its own 2D evacuation meshes If no fire related data is needed in the evacuation calculation then there are no need for fire meshes and FDS Evac can be run in an evacuation trial mode One should choose the dimension and mesh cell sizes of these evacuation meshes such that the position of different evacuation specific objects like DOOR EXIT is easy to give This means that the Ax and Ay should be some nice round figures The present version of FDS Evac does not move these kind of objects to the mesh cell boundaries like is done for
47. ler effect is the way how the grid resolution changes the evacuation flow fields used to guide humans to the exit doors In some cases a finer grid does always mean a better guiding field for humans If the evacuation grid resolution is much less than the half of the body dimension then one may find some difficulties to obtain nice evacuation flow fields see the IMO test case 10 in The FDS fire calculation grid has effects on the evacuation calculation via the smoke toxic gas tem perature and radiation level calculation How accurate are the predictions of FDS for the fire products will of course depend on the FDS grid resolution See the FDS Technical Guide for the effects of the grid reso lution on the FDS fire calculation The evacuation calculation interpolates the fire calculation results to the 2D evacuation grids and the evacuation grid resolution will have an effect on the spatial accuracy of this fire related information but usually grid sizes are equal or less than the dimensions of a human body and thus the accuracy of the fire information in the evacuation grids is fine enough 19 a m 2m 10m 2m a lt _ lt a B 7 a 24 Sheps pe fa gee ae as C a aoa Ll i i ow oe 2m m nana ata z En y 1 om a I y gt al Jae p m mE m f Jm 10m re mm mm mb a neg m oo
48. lied 8 14 The CORR Namelist Group Defines stairs or a horizontal corridor One uses these to move humans from one floor to the next one The corridor actually stairs model is a really simple one One gives the length of the stairs and reduces the movement speed One also gives the maximum number of persons inside the corridor For now there is no relation between the density and the movement speed or human flow inside the corridor 33 ID ID string of the corridor One can refer to this CORR by its name MAX_HUMANS_ INSIDE how many humans fit inside the corridor XB XB1 XB2 Used to specify the points where the smoke and FED data is taken for this corridor stair If only one value is used for the corridor stair give XB If the values at the beginning and at the end of the corridor stair is used give both XB1 and XB2 respectively EFF_LENGTH length of the corridor movement time EFF_LENGTH FAC_SPEED xv A FAC_SPEED How much slower humans move in the corridor e g stairs compared to the target speed v in floors TO_NODE Where humans are going when leaving this corridor To_node can be DOOR EXIT CORR or ENTR Note that CORR is usually used to define stairs between floors Doorgna ggg Corr Dooryst foor Stairs could also be constructed using the EVSS namelists correctly but this is not as straight forward as to use CORR constructions 8 15 The EVSS Namelist Group Defines an incline e g stairs or spectat
49. metry by changing objects like OBST VENT HOLE and MESH Define your person classes the PERS namelist groups These define the properties of the humans in the model Also the detection and reaction time distributions are given here Define your doors exits stairs and entries the DOOR EXIT CORR and ENTR namelists Activate meshes in Smokeview to see the actual positions of your obstacles in the evacuation meshes which might be a little bit different than the values given in the input file due to the fact that FDS moves OBSTs HOLEs and VENTs to match the mesh cell boundaries See Sec 1 2 and Fig 2 how doors should be defined Place the humans inside the building the EVAC namelists Use EVHO namelists if needed Note that humans should not be placed behind the exits or doors but this is no problem because exits and doors are usually defined on solid OBSTs Once again run a short simulation See that your humans have correct initial positions Edit the initialization file of Smokeview smokeview ini or CHID ini to make the squares that repre sent humans larger by changing the value of PARTPOINTSIZE Note that now you had the file CHID_evac eff on your disk so this file was read in i e the human flow fields were not recalcu lated and the calculation runs faster than before 24 7 2 e Run a longer simulation and see that the humans are moving correctly i e they are following correct flow fields and the exits stai
50. n boundary condition is used to calculate the evacuation flow fields amp SURF ID OUTFLOW VEL 0 00001 TAU_V 0 1 Define the evacuation vents for the main evacuation mesh there should be an evacuation vent at every place where humans can go inside some door exit etc object This vent is not at an outer boundary of the domain nor at a solid object thus there should be an OBST behind it Left Exit amp VENT XB 0 20 0 20 4 40 5 60 0 40 1 60 SURF_ID OUTFLOW MESH_ID MainEvacGrid EVACUATION TRUE RGB 0 0 255 amp OBST XB 0 40 0 20 4 40 5 60 0 40 1 60 SURF_ID INERT EVACUATION TRUE RGB 30 150 20 This vent is at the outer boundary of the domain i e it is on a solid object thus no need for an OBST behind it Right Exit amp VENT XB 11 60 11 60 4 40 5 60 0 40 1 60 SURF_ID OUTFLOW MESH_ID MainEvacGrid EVACUATION TRUE RGB 0 0 255 An exit namelist defines an exit door which takes humans out of the calculation EXIT ID LeftExit IOR 1 FYI Comment line VENT_FFIELD LeftExitGrid XYZ 0 20 5 00 1 50 XB 0 20 0 20 4 40 5 60 0 40 1 60 amp VENT XB 0 20 0 20 4 40 5 60 0 40 1 60 SURF_ID OUTFLOW MESH_ID LeftExitGrid EVACUATION TRUE Left Exit Fan SEXIT ID RightExit IOR 1 FYI Comment line 39 VENT_FFIELD RightExitGrid XYZ 9 80 5 00 1 50 XB 1
51. n the MESH lines The present version of FDS Evac places the different evacuation objects to the different evacuation meshes according to their x y z co ordinates by default One object should belong only to one main evacuation mesh It the position of the evacuation objects like exits and doors is ambiguous then a keyword MESH_ID should be given to specify the correct main evacuation mesh There are many keywords which might be given in the FDS Evac input file and these are also read in but the values are not used yet This manual only explains keywords which actually have some effect on the calculation If one looks the evac f90 source code one finds a quite many non used keywords The positions of doors and exits are not checked i e the user should give VENTs and OBSTs so that in the final FDS Evac calculation geometry there is an evacuation VENT every EXIT and DOOR in the main evacuation meshes or otherwise humans can not enter these doors because they feel repulsive forces exerted by the solid objects behind the doors It is good idea to put an exit or a door a little bit inside a hole in the wall see Fig 2 This makes the door flow better because then the door posts will exert forces on humans Check your EVAC lines that you are not putting humans in areas where humans should not be Check also that humans can not go out of bounds i e that there are no openings in the evacuation geometry where no door nor exit is def
52. namics Simulator FDS Detailed information about FDS can be found in its documentation and more detailed information about the evacuation algorithm can be found in the next section 2 1 Name and Version of the Model The name of the underlaying fire simulation program is the NIST Fire Dynamics Simulator or FDS FDS is a Fortran 90 computer program that solves the governing equations of fluid dynamics and Smokeview is a companion program written in C OpenGL programming language that produces images and animations of the results The evacuation calculation module developed at VTT is implemented as subroutines of FDS and these subroutines together with the FDS are called as the FDS Evac The present version of FDS Evac is build on the FDS version 5 0 0 and it is the second version of the evacuation module and thus its version number is 1 10 i e FDS5 Evac1 10 Changes in the version numbers correspond to major changes in the physical models or input parameters For minor changes and bug fixes incremental versions are released referenced according to fractions of the integer version numbers In addition day to day bug fixes made in response to user feedback are referenced by a compilation dates that are printed at the top of the diagnostic output file 2 2 Type of the Model FDS Evac is an combined agent based egress calculation model and a Computational Fluid Dynamics CFD model of fire driven fluid flow where the fire and egress parts are inte
53. ncy of FDS is due to the simplicity of its rectilinear numerical grid This can be a limitation in some situations where certain geometric features do not conform to the rectangular grid The numerical grids used by the movement algorithm of FDS Evac are a two dimensional cut offs the FDS grids thus the same limitations apply to the evacuation part of the code The present version to the evacuation module can also treat inclines like wide stairs and spectator stands which are along the x or y direction of the underlaying rectangular mesh The grid cell size determines the finest details which can be modelled by the program and the geometry of the building is discretized e g the widths of the doors are integral multiples of the grid cell sizes Reduced Visibility The smoke consentration calculated by the FDS is used to slow down human move ment using the results of a recent experiment by Frantzich and Nilsson 17 where larger smoke consentra tion were used than in the experiments by Jin 18 There are large scatter in the experimental results and more experimental results are more than welcome The default model for stairs does not include the option for humans to turn back when the smoke consentration becomes too high Incapacitation The incapacitation model used the FED consept introduced by Purser 16 but the large scatter between different humans is not taken into account in the current version of the program Whereas FDS is doing well for t
54. ne should not use the default values 8 10 The EVHO Namelist Group ID ID string XB where the humans are not put z should belong to a main evac mesh PERS_ID This hole apply just for this person type i e has effect only on those EVAC lines where PERS_TD matches EVAC_ID This hole apply just for on that EVAC line If both PERS_ID and EVAC_ ID are given they are treated using the logical operator OR EVAC_MESH If there are overlapping main evacuation meshes then this parameter could be used to specify the mesh where this EVHO line is applied 31 8 11 The EXIT Namelist Group Defines an exit Note that an outflow vent is not automatically created so the user should give a sepa rate VENT line Exits might be used just to count humans then the keyword COUNT_ONLY TRUE is used and thus these can be placed anywhere inside the building Humans which move through an exit COUNT_ONLY FALSE are removed from the calculation i e they are supposed to be gone outside of the building and be safe ID ID string of the exit One can refer to this exit by its name XB Co ordinates should be a line in the x y plane the z should belong to a main evacuation mesh IOR Direction of the door e g 1 humans are going z direction 2 humans are going y direction direction means room gt exit outside of the building COUNT_ONLY If true humans are not removed they are just counted default is false The CHID_evac c
55. nt of the entry is crowded FLOW_FIELD_ID Flow field in the room floor which this person is following i e specifies to which door a person tries to go if no known nor visible doors are available If not given the flow field of the main evacuation mesh is used KNOWN_DOOR_NAMES The ID strings of the known exit doors This only apply to persons that are gen erated at this entry by the MAX_FLOW i e it does not apply to those persons who are transfered to this entry from somewhere else 32 KNOWN_DOOR_PROBS The probabilities that the exit doors are known The known doors for the persons generated by this entry are drawn using these probabilities Default values are equal to ones XB coordinates should be a line in the x y plane the z should be main evac mesh z coordinates QUANTITY color of the squares in Smokeview of the humans which are entered at a specific flow rate If the humans are coming to this entry form some other node then their original color is used instead of QUANTITY This is used if the COLOR_METHOD 0 is specified on some PERS line PERS_ID the properties of humans are generated using these parameters if they are not coming to this entry form some other node i e they are new humans If not given default values are used EVAC_MESH If there are overlapping main evacuation meshes then this parameter could be used to specify the mesh where this ENTR line is applied 8 13 The DOOR Namelist Group De
56. o the fire the evacuees familiarity with the exits and the visibility of the exits The effect of these factors is taken into account by adding constraints to the evacuation time minimisation problem According to the three factors mentioned the exits are divided to seven groups so that each exits will belong to one group The groups are given an order of preference The familiarity of each exit for each agent can be determined by user in the input file of FDS Evac It is also possible to give a probability for the familiarity of an exit and FDS Evac will randomly set the familiarity of the exit FDS Evac determines the visibility of an exit to an agent by taking into account the 16 blocking effect of smoke and obstacles The possible blocking effect of other agents is not considered in the current version of the programme The existence of disturbing conditions is estimated from the fire related data of FDS on the visible part of the route to the exit By disturbing conditions we mean conditions like temperature and smoke that disturb an evacuee but are not lethal If there are lethal conditions on an exit route the exit has no preference The exit selection algorithm consists of the above described two phases First the exits are divided to the preference groups according to Table 2 Then an exit is selected from the most preferred nonempty preference group by minimising the estimated evacuation time According to socio psychological litera
57. on calculation If you are going to do run FDS Evac only in the evacuation trial mode then the fire grids are not used and the memory requirements might not be as large so you might be able to run just the evacuation calculation Save the fire input file to some other name and change also the CHID on the HEAD namelist group Put a keyword EVACUATION FALSE to every HOLE line which you fire input has Make a copy of each HOLE line which you want also to appear in the evacuation geometry and change EVACUATION value to TRUE This may sound like a nuisance but the way how FDS parses the input file demand that Add a line SURF ID OUTFLOW VEL 0 000001 TAU_V 0 1 to your input file Define meshes for the evacuation Each floor should have its own mesh The z co ordinate for these meshes should be at a level where the most obstacles for the movement are usually about one meter above the floor See Fig 8 and Sec 8 1 23 Put T 0 0 on the TIME namelist group comment out the fire meshes i e remove ampersands at the beginnings of the fire mesh lines and run FDS Evac Use Smokeview to see if the 2D geometry is looking right You can play around with the Zmin and Zmax to take the evacuation layout at different heights Define additional obstacles with EVACUATION TRUE where you do not want humans walking No need to define SURE _ ID for evacuation obstacles because the default for these is INERT Make additional holes wi
58. on Simulation and the State of the Art Fire Simulation Proceedings of the 7th Asia Oceania Symposium on Fire Science amp Technology 20 22 September 2007 Hong Kong McGrattan K B ed Fire Dynamics Simulator Version 4 Technical Reference Guide 85 p NIST Special Publication 1018 National Institute of Standards and Technology Gaithersburg MD 2004 McGrattan K B and Forney G P Fire Dynamics Simulator Version 4 User s Guide 90 p NIST Special Publication 1019 National Institute of Standards and Technology Gaithersburg MD 2004 Forney G P and McGrattan K B User s Guide for Smokeview Version 4 96 p NIST Special Publication 1017 National Institute of Standards and Technology Gaithersburg MD 2004 Helbing D and Molnar P Social force model for pedestrian dynamics Physical Review E 51 4282 4286 1995 Helbing D Farkas I and Vicsek T Simulating dynamical features of escape panic Nature 407 487 490 2000 Helbing D Farkas I Molnar P and Vicsek T Simulating of Pedestrian Crowds in Normal and Evacuation Situations Pedestrian and Evacuation Dynamics Schreckenberg M and Sharma S D eds Springer Berlin 2002 pp 21 58 Werner T and Helbing D The social force pedestrian model applied to real life scenarios Pedes trian and Evacuation Dynamics Proceedings of the Seconnd International Conference University of Greenwich L
59. ondon 2003 pp 17 26 P A Langston R Masling B N Asmar Crowd dynamics discrete element multi circle model Safety Science 44 395 417 2006 Simulex Evacuation Modelling Software User s Guide Integrated Environmental Solutions Ltd Glasgow Scotland UK 1996 48 p Pan X Computational Modeling of Human and Social Behaviors for Emergency Egress Analysis 127 p PhD Thesis Stanford University CA 2006 P A Thompson and E W Marchant A Computer Model for the Evacuation of Large Building Popu lations Fire Safety Journal 24 131 148 1995 P A Thompson and E W Marchant Testing and Application of the Computer Model Simulex Fire Safety Journal 24 149 166 1995 P Thompson H Lindstrom P Ohlsson S Thompson Simulex Analysis and Changes for IMO Compliance Proceedings of 2nd International Conference Pedestrian and Evacuation Dynamics pp 173 184 2003 52 16 Purser D A Toxicity Assessment of Combustion Products in SFPE Handbook of Fire Protection Engineering 2 ed pp 2 28 2 146 National Fire Protection Association Quincy MA 1995 17 Frantzich H and Nilsson D Utrymning genom t t rok beteende och f rflyttning 75 p Report 3126 Department of Fire Safety Engineering Lund University Sweden 2003 18 Jin T Visibility through Fire Smoke Journal of Fire amp Flammability 9 135 155 1978 19 Proulx G A
60. or stand or an escalator The defined incline could also be hori zontal Then it specifies a piece of the current floor at different vertical position than given on the MESH line of the evacuation floor The z co ordinates of the EVSS constructions are only used to plot the humans in correct positions when they are viewed by Smokeview The human movement algorithm uses only the x and y ID ID string of the incline XB co ordinates should define a plane in the x y plane the z should belong to a main evacuation mesh EVAC_MESH If there are overlapping main evacuation meshes then this parameter could be used to specify the mesh where this EVSS line is applied IOR direction of the incline e g 1 means that the x edge of the EVSS plane is touching the main evacuation plane defined by the z of XB HEIGHT The height of the incline measured from the level of the main evacuation plane defined by the z of XB The other edge opposite to the IOR edge of the incline has z zx height HEIGTH can have a positive or a negative value HEIGHTO The height of the base line of the incline measured from the level of the main evacuation plane defined by the z of XB The IOR edge of the incline has z zx height0 HEIGTHO can have a positive or a negative value If HEIGHTO HEIGHT the EVSS defines a horisontal plane and IOR has no effect FAC_VO_UP The unimpeded speed of a human upwards the plane is v FAC_VO_UP x vo FAC_VO_DOWN The un
61. ould have EVAC_HUMANS FALSE or just no EVAC_HUMANS keyword at all False is the default Note that these meshes should have exactly the same IJK and XB definitions as the corresponding main evacuation meshes This is not checked by the program so the user should do the check 8 2 The TIME Namelist Group EVAC_DT_FLOWFIELD is the time step of the calculation of the evacuation flow fields These fields are calculated before the fire and evacuation calculation i e simulation time has negative values Default is 0 01 s EVAC_DT_STEADY_STATE is the maximum time step of the human movement algorithm this should not be too large should not be larger than 0 1 s This parameter defines the minimum coupling frequency of different main evacuation meshes Coupling is faster if the time step of the fire calculation is shorter Default is 0 05 s 8 3 The SURF Namelist Group One should always define a new surface type for the evacuation calculation which is used to construct the flow fields that guide the humans to the doors or to other targets see Figure 4 and the FDS Evac Technical Reference Guide for details The following line should be given on the input file amp SURF ID OUTFLOW VEL 0 000001 TAU_V 0 1 Note that VEL should be a really small number otherwise one might not get a nice 2D potential flow solution 8 4 The MISC Namelist Group EVAC_SURF_DEFAULT is the surface default for the evacuation meshes The default
62. override the default values of different parameters Note that the FDS Evac is still under construction and so is this manual See the example FDS Evac calculations and read through the example input files on the FDS Evac web page These example input files contain many comment lines which explain all the major features of the FDS Evac input file format and how to do a FDS Evac simulation Some general notes on FDS Evac and some special features and warnings are listed below New meshes must be defined for the evacuation calculation part These meshes are not related to the fire calculation meshes i e their dx and dy may be different and the spatial extent of the meshes may also be different Usually one defines one main evacuation mesh per one floor of the building if the spaces on this floor are connected If there are more than one evacuation zone on a given floor then different main evacuation meshes may be used for this floor The evacuation input should be matched to the evacuation floor mesh definition Check the actual locations of the obstacles using Smokeview The evacuation related input e g namelists DOOR EXIT ENTR and EVAC is not moved to the closest mesh points For now Smokeview does not show these evacuation related objects In the evacuation meshes all obstacles are thick i e they fill at least one mesh cell in each direction x and y The evacuation meshes are two dimensional i e they should have IJK N Ny 1 o
63. p TAIL 49 12 Conclusion The FDS Evac is under construction The next things to be implemented are Merging flows in corridors and stairs A more realistic CORR object Record the position of each human inside the corridor stairs and use the equations of motion to model the movement in the corridor stairs More pre defined human classes especially those refered in the IMO circular 21 Elevators More intelligence in the exit door selection algorithm e g estimated queueing time due to the other humans heading towards the same exit door Social interactions like herding etc Sreading of the information human to human communication Some support to the parallel version of the FDS5 The fire related information the CHID_evac fed file should be saved when doing parallel calculation Easier generation of the input file The present status of the FDS Evac is Smoke vs walking speed correlations are included Fractional Effective Dose is calculated and used to incapacitate humans Smoke density can be used to trigger human movement Simple exit door selection algorithm is implemented Inclines stairs escalators can be modelled explicitely by using the equations of motion for each person Simple stair algorithm without merging flows If there are merging flows in staris then these should be modelled explicitely which means some additional work to construct the input file The flows through doors stairs and
64. racting FDS Evac can also be used just to calculate the egress problem without any fire driven fluid flow calculation 2 3 Model Developers The evacuation module of FDS was developed and its currently maintained by the VTT Technical Research Centre of Finland VTT A substantial contribution to the development of the mode and its implementation as a module of FDS was made by the Fire Research Division in the Building and Fire Research Laboratory at the National Institute of Standards adn Technology NIST Additional contributors and co workers are cited in the Acknowledgments 2 4 Relevant Publications Each version of FDS Evac is documented by this publication the FDS Evac Technical Reference and User s Guide The User s Guide part of the publication the mechanics of using the computer program The Technical Reference Guide part provides the theory and algorithm details plus a description of the verification and validation studies and details about hte many parameters of the evacuation model and their default values The model behind the movement algorithm of FDS Evac was introduced by Helbing et al 6 7 8 9 The implementation of this algorithm inside the FDS program environment was introduced by Korhonen Hostikka and Keski Rahkonen 1 Later the model was modified along the lines given in the paper by Langston et al 10 to a three circle representation of humans 2 2 5 Input Data Required to Run the Model All of the input p
65. rs and doors are working correctly Note that the reaction and detection time distributions given on the PERS lines should be shorter than the simulation time to see some human movement pre evacuation time detection time reaction time Do a full evacuation calculation and save the results i e the CHID_evac csv file Repeat this step a dozen or so times Note that the results are not exactly similar because humans have random properties and initial positions These simulations correspond to a fire drill After this activate the fire meshes i e put the ampersands back to the fire mesh lines and do a full FDS Evac simulation Now the fire and evacuation simulations are done at the same time and a file CHID_evac fed is written to hard disk This file can be used to run many evacuation simulations per one fire simulation i e no need to calculate the same fire for many times Note that the CHID_evac eff file is re calculated always when there are active fire grids If you are doing more than one evacuation calculation per one fire scenario as you should then save the CHID_evac eff and CHID_evac fed files after the previous step where fire and evacuation calculations were done at the same time Then comment the fire meshes out i e the ampersands away once again and rerun the case Copy the results CHID_evac csv to some other name and rerun once again etc For a given fire you should run the evacuation part a couple of dozen times
66. s block major exit routes On the other hand humans may influence the fire by opening doors or actuating various fire protection devices For now the effect of smoke on the movement speeds of humans and the toxic influence of the smoke are implemented in movement algorithm of FDS Evac The exit selection algorithm of the agents uses smoke density to calculate the visibility of the exit doors Smoke reduces the walking speed of humans due to the reduced visibility its irritating and asphyxiant effects Recently Frantzich and Nilsson 17 made experiments on the effect of smoke concentration on the walking speeds of humans They used larger smoke concentrations than Jin 18 and they fitted the following formula to the experimental values o v9 Ks a 6K 10 where K is the extinction coefficient K s m and the values of the coefficients a and 8 are 0 706 ms and 0 057 m s respectively The standard deviations are reported to be gg 0 069 ms and 0g 0 015 m s but only the mean values are used in FDS Evac i e there is no variation between the agents The toxic effects of gaseous fire products are treated by using Purser s Fractional Effective Dose FED concept 16 The present version of FDS Evac uses only the concentrations of the narcotic gases CO COz and O to calculate the FED value FEDtot FEDco x HVco FEDo 11 Note that the above equation does not contain the effect of HCN which is also narcotic
67. se any other than the pre defined person types in FDS Evac There are different sets of person types suited to different situations Standard egress UK regulations IMO requirements etc 6 Model Validation and Verification 6 1 Introduction 6 2 Comparisons with Test Data Case 1 RI Nightclub ToDo Case 2 Theatre at Tampere Finland ToDo Case 3 Stairs in an office building in Helsinki 6 3 Comparisons with Engineering Correlations See Section 5 3 Stair flows door flows corridor flows Here also comparison with other evacuation models for these simple test geometries 6 4 Comparisons with Other Evacuation Models See the FDS Evac web page where the following test cases have been reported Sports hall Eerikkil Open floor office Banque Populaire Assembly space 22 7 Running FDS Evac Running FDS Evac is similar to running FDS i e relatively simple All of the parameters that describe a given fire and egress scenario are typed into a text file that will be referred to as the fds or the input file In this document the data file will be designated as CHID fds In practice the user chooses the ID string CHID so that all of the files associated with a given calculation all have a common prefix In Section 11 an example input file will be presented Several other example files exists at the FDS Evac web site http www vtt fi fdsevac It is suggested that a new user start with an existing input file run
68. sv file has a column for each EXIT regardless if COUNT_ONLY is true or false VENT_FFIELD The ID string of the evacuation flow field behind this exit door The humans are guided to this exit door by the specified flow field FLOW_FIELD_ID Used if this exit is a target for some other evacuation element and there are no known doors nor visible ones available If FLOW_FIELD_1ID is not given then the main evacuation mesh flow field is used WARNING It is better to use a door or an entry instead of an exit if it is a target of some other evacuation element XYZ Co ordinates which are used in the exit door selection algorithm to decide if the exit is visible or not Default is the mid point of XB EVAC_MESH If there are overlapping main evacuation meshes then this parameter could be used to specify the mesh where this EXIT line is applied 8 12 The ENTR Namelist Group Defines an entry An entry can enter humans to the calculation at a constant frequency An entry with frequency zero can just be used as an end point of a corridor or some door This case corresponds to a one way door i e humans can only come out from this door ID ID string of the entry One can refer to this entry by its name IOR direction of the entry e g 1 humans are entering towards x direction 2 humans are entering towards y direction direction means somewhere entry room MAX_FLOW persons per second actual flow may be smaller if the area in fro
69. t hand side describes the motive force on the evacuating human Each human tries to walk with his her own specific walking speed vu Iv towards an exit or some other target whose direction is given by the direction of the field v The relaxation time parameter 7 sets the strength of the motive force which makes a human to accelerate towards the preferred walking speed The human human interaction force in Eq 2 has three parts For the social force term ERS the anisotropic formula proposed by Helbing et al 8 is used Pe to i Nias 1 cos yj 1500 Aje Catal a 1 2 ny 3 where r is the distance between the centres of the circles describing the humans d is the sum of the radii of the circles and the vector n is the unit vector pointing from human j to 2 For a three circle represen tation of humans the circles used in Eq 3 are those circles of the two humans which are closest to each other The angle is the angle between the direction of the motion of human 2 feeling the force and the direction to the human j which is exerting the repulsive force on human i The parameters A Bi and A could be different for each human but in the present version of FDS Evac they have same values for each human The psychological wall human interaction ES is treated similarly but values Aw Bw and Ay are used for the force constants The physical contact force between humans E is given by fg k dij Tij caAv Nni
70. te humans Smoke density is used both to slow down walking speeds of humans and to affect the exit selection algorithm of humans Smoke density can also be used to detect the fire but is should be kept in mind that human nose is a very delicate instrument and the levels of smoke consentration needed for a sensation of smoke are well below the prediction capabilities of the current FDS fire model The evacuation part of the FDS Evac is stochastic i e it uses random numbera to generate the initial positions and properties of humans and there are also a small random force on each human s equation of motion Thus same results are not obtained for a given input file if multiple simulations are done For this reason one should always do a dozen or so egress simulation to see the variation of the results For this reason it is made posible to do many egress calculation per one fire simulation Also the calculation of the evacuation flow fields used to guide human movement need to be calculated only once to each given geometry The present version of FDS Evac does not use optimally computer memory and does not support par allel CPU calculations In later versions of the program the memory usage is more optimal and also the fire simulation part can be run using parallel CPUs to produce smoke and gas concentration informtion to the evacuation part 2 Model Documentation This section provides a short description of the evacuation module of the Fire Dy
71. th EVACUATION TRUE where they are needed Usually these are needed at exits or doors See Fig 2 and Sec 1 2 Run FDS Evac T 0 0 and see if the 2D geometry is looking correct If not correct it by adding more OBSTs and HOLEs Define evacuation flow field vents EVACUATION TRUE SURF_ID OUTFLOW that suck fluid out of the evacuation meshes at the places where you want humans to go These vents should be placed at the doors and exits Note that in FDS5 vents should be defined on solid surfaces If you are using multiple human flow fields on a floor then you should specify the MESH_ID on the VENT lines This specifies the evacuation mesh where this vent is put Same applies to holes and obstacles as well but usually one can use same obstacles and holes on each flow field Remember to define slice output files at your evacuation mesh heights e g amp SLCF PBZ x x QUANTITY VELOCITY VECTOR TRUE Remove CHID_evac eff file if it exists Run a short simulation i e put T 1 0 Check the human flow fields by using Smokeview Check also that your evacuation geometry looks fine If not add obstacles or holes to the evacuation calculation and remember to remove the CHID_evac eff file Repeat these steps as long as you are satisfied with the geometry Note that FDS Evac tries to read the human flow fields from the disk if there exitst a CHID_evac eff file This file should be recalculated each time when you make changes to the geo
72. the standard FDS fire simulation geometrical objects like OBST HOLE and VENT Evacuation meshes should not be too fine because then one might face problems with the evacuation flow fields which are used to guide human movement towards the exits This dificulty can be addressed by an experience user but an easier way is always to use evacuation meshes which are not too fine Usually mesh cell sizes 0 25 m or more can be used without any problems For example if you have 1 2 m wide doors you could use 0 3 m 0 6 m or 1 2 m cell spacing depending on how detailed geometry is needed Note that Smokeview does not H La ly 5 l Outflow l VENT 4 Human Wall Evacuation Forces HOLE l EESE i EXIT i or i DOOR Figure 2 How to make an exit or a door yet fully support the evacuation calculation e g the positions of doors stairs and other evacuation objects are not shown by Smokeview A door should be defined such that it is a little bit inside a wall see Fig 2 This way door casings will produce forses on humans One should make a small hole in the wall where an exit or a door is put Note that the width of the exit will depend on your mesh resolution One should define the exit such wide that it will cover the whole width of the hol
73. they would be alive Finally the last column is the maximum FED value of the humans which are alive Human movement may be visualized by Smokeview where Evacuation is shown on the Load Save menu The humans are saved on prt5 files During the run of FDS Evac lots of evacuation information is printed on the standard error If you want to save this information you should redirect the standard error to some file Read your DOS or Unix Linux manual how to do this 2 amp gt 1 gt CHID err The file CHID_evac eff contains the converged human flow fields and the file CHID_evac fed contains the smoke and gas concentration information These might be used later if more evacuation calcu lations are done using same geometrical information e g if one is doing a Monte Carlo simulation of the egress scenario 36 Figure 9 Example 1 Evacuation and fire calculation geometries 11 Sample Calculation Below two example inputs files of FDS Evac are given These input files are not representing any real building they are just used to show some of the keywords and parameters which can be used in FDS Evac egress calculation The first input file specifies a fire in a room with two doors see Fig 9 Humans are using both doors and they select the door by using the exit door selection algorithm thus each of the two doors needs its own evacuation flow field This means that one needs to define the main evacuation mesh and two additional door
74. tion lines and keywords if there is no active evacuation meshes Main evacuation meshes have also a keyword EVAC_HUMANS TRUE which says that this mesh will contain humans Usually one main evacuation mesh represents a floor You need more main evacuation meshes on a floor if there exists separate parts of the floor where the humans are not going to be using same exit routes In principle you could manage by one main mesh but the calculation is faster if you define different meshes for the parts which do not interact with each other All evacuation meshes should have a name i e a keyword ID should be given on the amp MESH line The 27 name of the mesh should not be too long max 26 characters Of course the names of different meshes can not be the same The ID is used later to specify the mesh where some additional evacuation objects are placed Evacuation meshes should have only one cell in the z direction i e they are two dimensional horizontal meshes see Figure 8 Choose IJK and XB so that the dx and dy are nice round numbers which will fit nicely to your geometry You should give the positions of all evacuation objects as multiples of dx and dy This is not obligatory but one makes less mistakes this way FDS Evac does not move the evacuation objects to the closest mesh points yet this may change in later versions of FDS Evac Evacuation meshes which are only used to calculate additional human movement flow fields sh
75. tion meshes should all have an unique ID string defined amp MESH IJK 60 54 1 XB 0 4 11 6 0 4 10 4 0 4 1 6 EVACUATION TRUE EVAC_HUMANS TRUE ID MainEvacGrid amp MESH IJK 54 54 1 XB 0 4 10 4 0 4 10 4 3 0 4 2 EVACUATION TRUE EVAC_HUMANS TRUE ID MainEvacGrid2 Additional door flow fields Note same amp MESH amp MESH amp MESH amp MESH amp TIME amp MISC amp DUMP amp REAC amp SURF main evacuation grid and the door flow grids should have XB and IJK IJK 60 54 1 XB EVACUATION TRUE IJK 60 54 1 XB EVACUATION TRUE TJK 54 54 1 XB TJK 54 54 1 XB EVACUATION TRUE TWFIN 200 0 EVACUATION TRUE 0 4 11 6 0 4 10 4 0 4 1 6 ID LeftExitGrid Left lst floor 0 4 11 6 0 4 10 4 0 4 1 6 ID RightExitGrid Right lst floor 0 4 10 4 0 4 10 4 3 0 4 2 ID LeftDoorGrid2 Left 2nd floor 0 4 10 4 0 4 10 4 3 0 4 2 ID RightDoorGrid2 Right 2nd floor SURF_DEFAULT WALL NFRAMES 200 DT_PART 0 5 DT_HRR 1 0 DT_SLCF 1 0 DT_PL3D 10 0 DT_ISOF 10 0 ID POLYURETHANE FYI C 6 3 H7 1N 02 1 SOOT_YIELD 0 10 N O Cc 6 3 H se O DA y ID BURNER HRRPUA 1000 43 NFPA Handbook Babrauskas PART_ID smoke COLOR RASPBERRY amp MATL ID GYPSUM
76. torso and shoulder circles see Ta ble 1 and Fig 1 The variation of the diameters is determined by the variation of the human circle 2Ra TAU_ROT relaxation time Tf for the rotational equation of motion see FDS Evac Technical Reference Guide M_INERTIA moment of inertia 17 for the rotational equation of motion see Eq FAC_A_WALL A for walls is FAC_A WALLxA FAC_B_ WALL By for walls is FAC_B_ WALL B LAMBDA_WALL Aw for walls FC_DAMPING Damping coefficient cg of the radial contact force see Eq 0 V_ANGULAR Maximum target angular speed of a human w see Eq NOISEME NOISETH Gaussian noise see Eqs These parameters determine both the noise in the translational equation and the noise in the rotational equation COLOR_METHOD How humans are shown in Smokeview see Table Default value is 0 NOT_RANDOM If true do not use random seed when generating the initial positions and characteristics of humans Default is false 30 NOTE FAC_x_ WALL LAMBDA WALL FC_DAMPING V_ANGULAR NOISExx COLOR_METHOD NOT_RANDOM the last values read from PERS lines are used So it is nice practice to give these numbers just in one PERS group or have same numbers in every PERS group WARNING Change only the reaction and detection time parameters other parameters should have the default values and use the pre defined person types unless you know what you are doing 8 9 The EVAC Namelist Group Places
77. tuation torque and Mf t is the total torque exerted on the human by its surroundings M Mf EM FM 6 where My M and M are the torques of the contact social and motive forces respectively The torque of the contact forces is calculated as Mj Ri x ff 7 where R is the radial vector which points from the centre of human to the point of contact In FDS Evac also the social forces exert torques on humans and these are given by the formula Mg RE x 8 8 where only the circles which are closest to each other are considered The vector R7 points from the centre of human 2 to the fictitious contact point of the social force see Fig 3 Analogous to the motive force the first term on the right hand side of Eq 2 a motive torque is defined as fe Swen MI pitt fu 1 E 62 wl 0 2 2 where w is the maximum target angular speed of a turning human w t the current angular velocity y t the current body angle and is the target angle i e where the vector v is pointing The target angular 13 1 5 amp 4 UYUN 1 T 1 l 1 ss fF fA Fe FUNNY f f Y Y x x kS LN y eA TXNNN F Z2Aez TT Ce AA Pe ye AS iif Figure 4 A 2D flow field used to guide humans to the exit doors In this case only the left exit has an outflow boundary condition i e this fictitious human flow field is used to find the left exit only The main evacuation mesh shoul
78. ture 12 19 the familiarity of exit routes is an essential factor influencing decision making This is because the unknown factors related to unknown routes are considered to increase the threat As a result evacuees prefer familiar exit routes even if there are faster unfamiliar routes available For this reason emergency exits are used rarely in evacuations and fire drills 3 5 Groups According to socio psychological literature a crowd consists of small groups like families that tend to act together 12 This behaviour should be taken into account when building evacuation models A method for modelling this grouping behaviour with the equations of Helbing was developed In the model the actions as e Sat vice Stage the REES members walk towards each other to gather the group 2 In the egress stage the group moves together along the selected exit route These two stages are modelled by altering the preferred walking direction field of Helbing s equation of motion In the gathering stage the pedestrians are trying to move towards the centre of the group When the distances from the centre to each pedestrian are under a threshold value the group is considered to be complete When a group is complete it starts to move towards an exit This means that each group member is set to follow the same flow field While moving towards an exit the group members also try to keep the group together This is modelled by adjusting the walking speeds and
79. utes to the chosen exit door or when the user is allowing more than one exit door per a flow field The analogy to an incompressible fluid flow is not a bad starting point to find the movement directions of large human crowds For example when humans are leaving a large sports or entertainment event they usually just follow the human flow to the outside of the building without much control on the process The human movement method presented in Eqs 1 9 has many parameters Some of these parameters are related to physical dimensions of humans like m and 17 but many parameters are related to the chosen model Some of these parameters are chosen to be the same as found in the literature 7 10 and some are estimated from test calculations The parameters of the social force were chosen such that the specific human flows through doors and corridors were appropriate The parameters for the three circle representation of human contact forces and the rotational degrees of freedom were selected mainly by trial and error in order to obtain reasonably realistic human movement Monte Carlo simulations were done to see which are the most important model parameters and further analysis was focused on those parameters The first choice for the social force parameters of human human interaction was A 2000 N B 0 04 m and A 0 5 For the human wall interaction values A 2000 N B 0 08 m and A 0 2 were used It was noticed that these values are not
80. vac This model is shortly described below For a longer description see the papers by Helbing s group 6 7 8 9 and references therein For the modification of the one circle representation of a human to a three circle one see the papers by Langston et al 10 and Korhonen et al 2 3 2 Human Movement Model FDS Evac uses the laws of mechanics to follow the trajectories of the humans during the calculation Each human follows his her own equation of motion 2 TAD 10 60 o where x t is the position of the human i at time t f t is the force exerted on the human by the sur roundings m is the mass and the last term t is a small random fluctuation force The velocity of the human v t is given by dx dt FDS Evac treats humans as combination of three elastic circles moving on a two dimensional plane 10 These circles are approximating the elliptical shape of the human body similarly as in the Simulex model 11 and in the MASSEgress model 12 see Fig 3 The default body dimensions and the unimpeded walking speeds of different predefined human types of FDS Evac are listed in Table 1 The force on human 7 has many components mi m p A U Pee O 2 Hi w k where the first sum describes human human interactions the sum over w describes human wall interac tions and the last term por may be used for other human environment interactions like the fire human repulsion The first term on the righ
81. xperience any social forces from the other humans and whose target movement speed vP is set to zero The size of an incapacitated human is not changed i e he she remains on his her feet This is a very crude model and it needs to be modified in later versions of FDS Evac 3 4 Exit Selection Game theoretic reaction functions and best response dynamics are applied to model the exit route selection of evacuees In the model each evacuee observes the locations and actions of the other evacuees and selects the exit through which the evacuation is estimated to be the fastest Thus the exit selection is modelled as an optimisation problem where each evacuee tries to select the exit that minimises the evacuation time The estimated evacuation time consists of the estimated time of walking and the estimated time of queueing The walking time is estimated by dividing the distance to the exit by the walking speed The estimated time of queueing is a function of the actions and locations of the other evacuees It is also assumed that people change their course of action only if there is an alternative that is clearly better than the current choice This behaviour is taken into account by subtracting a parameter from the estimated evacuation time of the exit currently chosen Apart from the locations of exits and the actions of other people there are also other factors that in fluence the evacuees decision making These factors are the conditions related t

FDS+Evac – Technical Reference + User's Guide

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FDS+Evac – Technical Reference + User's Guide