PyroSim Example Guide 2007.2
Contents
1. Click Particle Injection tab Click the Emit Particles checkbox Surface Supply Vent Description Color mmm Texture Surface Type Supply Air Flow Temperature Species Injection Particle Injection Normal Flow Rate Specify Velocity 8 33 Specify Volume Flux Specify Total Mass Flux 5 Specify Mass Flux of Individual Species Tangential Velocity 0 0 0 0 Slip Index 0 5 Ramp Up Time Default 1 0 Wind Profile Top Hat Default v Click OK to save the changes and close the Edit Surfaces dialog ft s 2 5 Ibj Ft s 5 Apply OK Cancel Figure 5 14 Creating the supply vent surface In this model we will not explicitly represent the return duct Instead we will position the return vents on the outer boundary This has the advantage of simplicity and allows us to define these vents as open to the atmosphere To add the return vent to the model 46 Switchgear Fire Example In the Description box type Return Vent 3B On the Model menu click New Vent In the Group list select Vents In the Type list select OPEN In the Lies in the plane list select Y and type 0 0 This places it just barely outside the duct for visualization A word of caution In most cases this slight offset will not cause any problem since both the vent and duct will be moved to the same mesh coordinates during the solution However it c2. een 12 Add a Temperature Measurement Device 13 Add a Temperature Slice Plane e 13 S ve th Model xn eb e dr ta aed a et Rex e rd eee d Re 14 Run the Simulation erede uve eor Quse iret 14 View Smoke in eoe eee ure dinde ree eere 15 View Temperature Slice Plane sess 15 View Temperature Measurements nennen hehehe nennen 16 4 Smoke Layer Height and Heat Flow Through a Door eee 17 Create the Burner Surface i a e iiia 17 Create the Burner Vent e at oce ebd ee aeg esed 18 Create the Open Side Vent niece epe tee eerie reete riprese 19 Create the Mesh voces ters ante eee dece IN Sedes abate toe teu dods 20 Add the Wall eee Eee ret eee oe EE pre e e Ede ERE Eres 21 Add the DoOr 1 2 Pie E E 21 Rotate the Model for a Better View 5 22 Adda Layer Zoning Device te o Pat dere ites 22 Add a Flow Measuring Device eene enhn enhn 23 set the Simulation tae gebe 23 Save the model 2 eon iet aes ee rie eri dere E epe reed eerte 23 Run the Simulation ee ED en ahaa PHP sei
3. 2 Click Copy and type 1 in the Number of Copies box 3 In the Offset box for X type 4 0 4 Click OK This will create Cable C 1 Double click and change the name to Cable D Copy to create cable E 1 Right click on Cable D and click Copy Move 2 Click Copy and type 1 in the Number of Copies box 3 In the Offset box for X type 20 0 4 Click OK This will create Cable D 1 Double click and change the name to Cable E 44 Switchgear Fire Example If wanted you could add additional cables We will stop here The cables are shown in Fig ure 5 13 File Edit Model Qutput FDS View Help ol ee 3 dh 5 IG sno ators Bg a Surfaces Cable mq Concrete Wall Bi Dividing Door Dividing wall Bg Entrance Door Vent Entrance Door Blockag Switchgear cabinet 1 cabinet 2 cabinet 3 cabinet 4 5 4 Cables cable a cable B cabe c cape D cable E 3D View 2D View Record View Figure 5 13 The room showing the cables Ventilation Each room has supply and return ventilation Vents have general usage in FDS to describe 2D planar objects In this case we will use vents to model components of the ventilation system No holes need to be created it is assumed that air is supplied or returned into duct work within the wall We will first create a vent group On the Model menu click New Gro
4. Table 5 3 Concrete properties NUREG CR 1805 Property Value Density 2400 kg m 3 Specific Heat 0 75 kJ kg K Conductivity 1 6 W m K 28 Switchgear Fire Example Table 5 4 Sheet metal properties generic Property Value Density 7850 kg m 3 Specific Heat 0 45 kJ kg K Conductivity 46 6 W m K Table 5 5 Cable properties NUREG CR 6850 Property Value Density 1380 kg m 3 Specific Heat 1 289 kJ kg K Conductivity 0 192 W m K Computational Mesh In this example we will use two meshes We will use relatively coarse meshes that should be refined for a final analysis In Room 3A the room on the right the cell size will be approximately 0 5 ft 0 1524 and in Room approximately 1 0 ft 0 3048 m We have selected a finer resolution in Room 3A to more accurately represent the geometry of the cable trays and to provide a finer resolution for the flow solution near the fire The two meshes much touch in order to transfer information between them We will position the common plane inside Room 3B so that the finer mesh includes all of Room 3A and the door between the rooms There is always a compromise between number of cells and acceptable solution time As de scribed this model will have 162 000 cells and run in approximately 8 hours on a single CPU computer This problem uses English units as the primary values for the geometry Switch to English u
5. 4 3D View 2D View Record View Figure 5 9 Display of the dividing wall We will use a Hole obstruction to represent the door A hole can defined in the model but not activate until a specified time or event In this case we will define a hole door between the rooms that will open 5 minutes 300 seconds after the start of the fire To add the dividing door to the model 1 On the Model menu click New Hole 2 In the Description box type Dividing Door 3 In the Group list select Walls 4 In the Bounding Box boxes enter the values in Table 5 9 The values are chosen thicker than the wall to ensure that the door takes precedence 5 Click the Activation Events tab 6 In the Time box type 300 In the Event list select Activate The hole will be created door open 300 seconds after the fire starts 7 Click OK to close the Aligned Hole Properties dialog Table 5 9 Dividing door dimensions X ft Y ft Z ft Min 28 25 11 25 0 0 30 75 17 25 8 0 37 Switchgear Fire Example We also will add the Room 3B entrance door We want this door to stay closed for 300 sec By default FDS assumes the boundary of a mesh is closed To define a door on the boundary we will first create an open vent on the mesh boundary then plug it with an obstruction that will be removed at 300 sec To add the entrance door to the model 1 2 3 6 7
6. Convective Heat Flux ie Ramp Up Time Defaut 1 Add From Library Rename Delete Figure 3 4 Defining parameters for the burner surface Create the Burner Vent In this example we use a vent and the previously created burner surface to define the fire 1 On the Model menu click New Vent 2 In the Description box type burner vent Figure 3 5 3 In the Type list select burner This specifies that the previously created burner surface will define the properties of the vent 10 Burner Fire with Tem perature Measurement 4 In the Lies in the Plane list select Z 5 In the Min X box type 0 5 and in the Max X box type 0 5 6 In the Min Y box type 0 5 and in the Max Y box type 0 5 7 Click to create the new burner vent Specification Activation Events Description burner vent Group di Model Type M burner E Specify Color Texture Origin m F Relative to object 00 Geometry m Lies inthe Plane Z 0 0 Normal Direction Automatic Recommended v Bounds MinX 05 MaxX 05 Figure 3 5 Creating the burner vent Create the Top Vent The top of the mesh is an open boundary 1 On the Model menu click New Vent 2 In the Description box type open top 3 In the Type list select OPEN This is a default surface that means this will be an open bound ary Click the Specify Color checkbox and th
7. 8 On the Model menu click New Vent In the Description box type Entrance Door Vent In the Group list select Walls In the Type list select OPEN In the Lies in the Plane list select Y and type 28 5 In the Min X box type 20 0 and in the Max X box type 26 0 In the Min Z box type 0 0 and in the Max Z box type 8 0 Click OK to save the changes and close the Vent Properties dialog To define the blockage in the entrance door 1 2 3 8 On the Model menu click New Obstruction In the Description box type Entrance Door Blockage In the Group list select Walls In the Bounding Box boxes enter the values in Table 5 10 The values are chosen thicker than the wall to ensure that the door takes precedence In the Surface Properties panel select Single and select Concrete Wall from the list Click the Activation Events tab In the Time box type 300 In the Event list select Deactivate The blockage will be created door open 300 seconds after the fire starts Click OK to close the Obstruction Properties dialog Table 5 10 Entrance door blockage dimensions X ft Y ft Z ft Min 19 5 28 0 0 0 Max 26 5 29 0 8 0 Switchgear Cabinets First make a switchgear group 38 Switchgear Fire Example 1 2 3 4 On the Model menu click New Group In the Parent Group list select Model In the Group Name box
8. Min 31 0 20 0 8 5 Max 58 0 23 0 9 0 Copy to create cable B 1 2 3 4 5 Right click on Cable A and click Copy Move Click Copy and type 1 in the Number of Copies box In the Offset box for Y type 14 5 Click OK to create a Cable A 1 Double click and change the name to Cable B Drawing cables C D is similar First 1 2 Click 2D View In the 2D View drawing tools toolbar left of window click the Draw an Obstruction tool 4 43 Switchgear Fire Example 3 To set the tool properties click Tool Properties 8 4 In the Min Z box type 9 5 5 In the Max Z box type 10 0 6 In the Surface Prop list select Cable 7 Click OK to close the New Obstruction Properties dialog 8 In the 2D View action toolbar top of window select Cables in the Group list To draw cable C 1 Press and drag the mouse approximating the dimensions of cable C shown in Figure 5 1 2 Inthe 2D View action toolbar top of window click the Select and Manipulate Objects tool 3 Double click on the cable to edit its properties 4 In the Description box type Cable C 5 In the Bounding Box boxes enter the values in Table 5 14 6 Click OK to close the Obstruction Properties dialog Table 5 14 Cable C Dimensions X ft Y ft Z ft Min 55350 3 0 9 5 Max 58 0 2 955 10 0 Copy to create cable D 1 Right click on Cable C and click Copy Move
9. On the Model menu click New Vent In the Description box type burner vent Figure 4 4 In the Type list select burner This specifies that the previously created burner surface will define the properties of the vent In the Lies in the Plane list select Z In the Min X box type 4 0 and in the Max X box type 5 0 In the Min Y box type 0 0 and in the Max Y box type 1 0 Click OK to create the new burner vent Vent Properties x Specification Activation Events Description burner vent Group di Model B burner Specify Color Texture Origin m Relative to object 00 Y 10 0 2 00 Geometry Lies inthe Plane Z 0 0 Normal Direction Automatic Recommended v Bounds MinX 40 MaxX 5 0 Figure 4 4 Creating the burner vent Create the Open Side Vent One side of the model is an open boundary 1 2 On the Model menu click New Vent In the Description box type open side Inthe Type list select OPEN This is a default surface that means this will be an open bound ary Click the Specify Color checkbox and then click the Color button to open the Surface Color dialog Select a light blue color and click OK 19 Smoke Layer Height and Heat Flow Through a Door 5 In the Lies in the Plane list select Y and type 5 0 6 In the Min X box type 0 0 and in the Max X box type 5 0 7 In the Min Z box type 0
10. The cables are supported by ladder trays These trays are relatively open to air flow and have relatively little thermal mass compared to the cables Therefore we will not model the details of the trays but will just model the cables First make a cables group 1 On the Model menu click New Group 2 In the Parent Group list select Model 3 In the Group Name box type Cables 4 Click OK to close the Create Group dialog To prepare to draw the cables 1 Click 2D View This will display the sketch grid 2 In the 2D View drawing tools toolbar left of window click the Draw an Obstruction tool 4 42 Switchgear Fire Example 8 To set the tool properties click Tool Properties 8 In the Min Z box type 8 5 In the Max Z box type 9 0 In the Surface Prop list select Cable Click OK to close the New Obstruction Properties dialog In the 2D View action toolbar top of window select Cables in the Group list To draw cable A 1 2 5 6 Press and drag the mouse approximating the dimensions of cable A shown in Figure 5 1 In the 2D View action toolbar top of window click the Select and Manipulate Objects tool Double click on the cable to edit its properties In the Description box type Cable A In the Bounding Box boxes enter the values in Table 5 13 Click OK to close the Obstruction Properties dialog Table 5 13 Cable A Dimensions X ft Y ft Z ft
11. ga HUFIDESHEAD 1006 Poyntz Ave Manhattan KS 66502 5459 785 770 8511 www thunderheadeng com in collaboration with The RJA Group Inc One Pointe Drive Suite 210 Brea CA 92821 6315 PyroSim Example Guide 2007 2 Example Guide Table of Contents 1s Before Starting eei A etes doe Pei e Prts e Ll debo e 1 Installs iM ts 1 dici REPE 1 Manipulating the 3D Image eee beret ee Ere eere ese ee dod 1 FDS Concepts and Nomenclature 1 2 Example Problems Provided with FDS 5 0 eee eeeeeeeececeeeeeeeeeeeeeeeseseeeeeeeeeeeeeees 3 Ethanol Pati Eire m 3 Box Burn eene a 4 Insulated Steel Column sorire nino 5 Water Cooling e e ER aereo habue did gea Eee 6 3 Burner Fire with Temperature Measurement e eee 8 Create the Mesh eite rete dec reet quee n eee d n ode dtes a are ee onda or ada 8 Create the Burner Surface nt denn ee E nae adunco e i n dee 9 Create the Burner Eo Epid e oap etae bees 10 Create the Top Vent recs tecti de cee ere Rx ERR Ede e E ddp e E Dx ed 11 Rotate the Model for a Better View
12. Isosurfaces are 3D plots that show the surface on which a quantity has a specified value We will save isosurface data for temperatures which is one way to define the location of a hot gas layer To define the isosurfaces 52 Switchgear Fire Example 1 On the Output menu click Isosurfaces 2 Click the Temperature checkbox 3 In the Contour Values column enter 50 100 150 200 250 where the contour values are separated by a space Figure 5 16 4 Click OK to close the Animated Isosurfaces dialog 4 U M M M M MN Output Quantity Contour Values Unit I re iae y y Soot Concentration Mixture Fraction mol mol 2 Soot Density Mixture Fraction ozjft Soot Volume Fraction Mixture Fraction mol mol V Temperature 50 0 100 0 15 Thermocouple er U velocity ft s j V Velocity ft s F Velocity ft s A Viscosity 5 a Visibility Mixture Fraction ft fts Water Vapor mol mol Figure 5 16 Defining the temperature isosurfaces Simulation Parameters To define the end time 1 On the FDS menu click Simulation Parameters 2 In the Simulation Title box type Switchgear Fire 3 In the End Time box type 600 s To define the surface to be used on the mesh boundary 1 On the Simulation Parameters dialog click the Misc tab 2 In the Default Surface Type
13. click Plot Time History Results 2 A dialog will appear showing the different types of 2D results that are available Select smoke devc csv and click Open to view the device output The first display will be the heat flow through the door Figure 4 11 3 To select a data set from a different sensor select that data in the left panel To view smoke layer height data click 1201 2 HEIGHT Figure 4 12 25 Smoke Layer Height and Heat Flow Through a Door r 15 Time History Plots Lelek door flow 50 1500 2000 2500 2000 2500 sO DO Time s I201 HEIGHT 00 500 1000 1500 2000 2500 2000 3500 000 DO Figure 4 12 Time history plot of heat flow through the door 26 Chapter 5 Switchgear Fire Example This example evaluates fire conditions in two adjacent switchgear rooms connected by a double fire door Figure 5 1 In the fire scenario a fire starts in a switchgear cabinet in room 3A The fire modeling results will used to estimate the time available for operators to conduct manual actions in one of the switchgear rooms This example was provided by Bryan Klein Klein 2007 28 8 8 6 m 288 8 6 Switchgear Room 3B Switchgear Room Appmx bc of fne supply du dg no vent 9 8 9 82 mx imate location of duct and vents Figure 5 1 Pictorial representatio
14. te Concrete Wall E Return Vent S Return Vent Supply Duct supply Vent 38 2 Sen 20 View Record View Figure 5 15 The room showing the vents Fire The fire is postulated to start in Room 3A in a switchgear cabinet Heat is released to the room through a vent in the side of the cabinet The size of the vent is 3 0 x1 0 and located 0 5 ft below the top of the cabinet We will model the fire as a surface with a specified heat release rate A surface type is used to specify the fire We will first create a fire group 1 On the Model menu click New Group 2 In the Parent Group list select Model 3 In the Group Name box type Fire 4 Click OK to close the Create Group dialog There are two additional steps to defining a fire First a surface will be created that defines the heat release rate Next the fire will be attached to the top of the switchgear cabinet Since the fire properties are specified in SI units 1 On the View menu click Units 2 Select SI 49 Switchgear Fire Example To create the surface that represents fire 1 On the Model menu click Edit Surfaces 2 In the Edit Surfaces dialog click New 3 In the Surface Name box type Fire 4 Select Surface Type and in the list select Burner 5 Click OK to close the New Surface dialog To change the properties of the Fire 1 In the Edit Surfaces dialog click to select Fire 2 C
15. 0 and in the Max Z box type 2 4 8 Click OK to create the open vent Create the Mesh In this example we will use mesh cells that are 0 17 m across This value is approximately 1 5 of the characteristic diameter D for a 800 kW fire As a rule of thumb this is as large as the mesh cells can be while still maintaining a moderate level of accuracy in modeling the plume U S NRC 2007 Using mesh cells that are smaller by a factor of 2 should decrease error by a factor of 4 but will increase the simulation run time by a factor of 16 1 On the Model menu click Edit Meshes 2 Click New Figure 4 5 The boundary dimensions will automatically be set to the correct size based on the two vents 3 In the X Cells box type 30 4 In the Y Cells box type 30 5 In the Z Cells box type 15 6 Click OK to save changes and close the Edit Meshes dialog Edit Meshes 2 E Specify Colo 7 Synchronize time step for tighter connection between meshes Mesh Boundary m MinX 0 0 MinY 0 0 MinZ 00 5 0 MaxY 5 0 MaxZ 24 Division Method Uniform 30 Cell Size Ratio 1 04 YCels 30 Cell Size Ratio 1 04 ZCels 15 Cell Size Ratio 1 00 Cell Size 0 17 x 0 17 x 0 16 Number of cells for mesh 13500 Figure 4 5 Creating the mesh 20 Smoke Layer Height and Heat Flow Through a Door Add the Wall In FDS obstructions are used
16. EE gt Em r EDS 9 amp 5 z 9 p 5 13 049 24 001 36 404 3D View 2D View Record View Figure 5 11 Making a copy of Cabinet 1 by dragging the vertical handle The final position will be 4 feet from the left and top boundaries Table 5 12 Dimensions for Cabinet 2 X ft Y ft Z ft Min 4 0 18 5 0 0 Max 20 0 24 5 8 0 We now copy both cabinets using the Copy Move menu You could alternately use the Trans late Objects tool as before l Using the Select and Manipulate Objects tool k press CTRL and click on both Cabinet 1 and Cabinet 2 2 Right click on either cabinet and click Copy Move 3 Click Copy and type 1 in the Number of Copies box 4 In the Offset box for X type 30 5 41 Switchgear Fire Example 5 Click OK 6 Change the cabinet names to Cabinet 3 and Cabinet 4 The cabinets are shown in Figure 5 12 Right click on the Bottom Wall and click Hide Object s to see inside the room You can always select Show All Objects to turn on an object display re SEE an All Floors aE dividing Wall Entrance Door Vent Entrance Door Blockag EJ Dividing Door E dib Switchgear Cabinet 1 cabinet 2 cabinet F cabinet 4 3D View 2D View Record View Figure 5 12 The rooms showing the switchgear cabinets Cable Trays
17. EM Ee Nue apost he ob decane 21 4 7 The model after rotating The burner is shown in red and the top vent in blue 22 4 8 The simulation dialog during the analysis 24 4 9 The initial Smokeview 1 1 24 4 10 3D smoke in the model 25 4 11 Time history plot of heat flow through the door ss 26 4 12 Time history plot of heat flow through the door see 26 5 1 Pictorial representation of the switchgear room complex showing switchgear cabi nets cable trays supply ducts and vents and smoke detectors Drawing not to scale 27 5 2 Completed model ret Ghee te i Shee ee aed oan 28 25 3 Input to create the mesh cedo tan woes 30 5 4 Display of the mesh scere 31 5 5 Concrete Properties He Eo 32 5 6 Composition of the concrete surface esses 34 2 7 i Whe CONC surface e p eR eer eM 34 5 8 Input for the wall dividing the two rooms 36 5 9 Display of the dividing wall e e eee a 37 5 10 Sketch of the lower left cabinet 40 5 11 Making a copy of Cabinet 1 by dragging the vertical handle The final position will be 4 feet from the left and top bo
18. box type 800 4 Click OK to save changes and close the Edit Surfaces dialog r Edit Surfaces ADIABATIC SurfaceID burner burner INERT MIRROR Color texture O OPEN Description 800 kW m2 burner Surface Type Burner X Heat Release Particle Injection Heat Release Heat Release Rate HRR 800 kw m Mass Loss Rate 0 0 kaf m s Ramp Up Time Default 1 0 s Extinguishing Coefficient 0 0 15 Temperature Surface Temperature TMPA Convective Heat Flux 0 0 kwim M Ramp Up Time Default 1 0 s Coo ww Emissivity 0 9 m Rename Delete Figure 4 3 Defining parameters for the burner surface Create the Burner Vent Vents have general usage in FDS to describe 2D planar objects Taken literally a vent can be used to model components of the ventilation system in a building like a diffuser or a return In these cases the vent coordinates define a plane forming the boundary of the duct No holes need to be created air is supplied or exhausted by the vent 18 Smoke Layer Height and Heat Flow Through a Door You can also use vents as a means of applying a particular boundary condition to a rectangular patch on a surface A fire for example can be created by specifying a vent on either a mesh boundary or solid surface The vent surface defines the desired characteristics of fire This is the approach used in this example 1 2
19. edere quee A et EP veia 23 View Smoke in ue eee Rr esr ere 24 View Time i tei o E Doe t ail eine 25 5 Switchgear Example Reiter Eee erp ehe tenente de ted Pea ende PE penes 27 Computational Mesh acc ciate e GC CV e ere 29 Material Properties e ts Es tede ede dei dokn e diese te tr dn 31 Save the Model lin es dele Ee coals edt ecd aedi 33 Surface Properties wc el hoe ie ee e d ee ae oes 33 Model Geometry 3 0 tr deretur te ve dyed PRESE PR Eee A dee dye E A 35 Post Processing Controls si dede dee 51 Simulation Parameters E a E to odo tota 53 iv Example Guide Analysis eed ee eere eet ep re iere ee eee ee ee View the Result oss torre eE reo cnn ne ev Rid esee viter reset References List of Figures 2 1 Ethanol model rin eee e REIR e Re dE Te rede 4 2 2 Bthanol pan results x eoo pene e bleue EE nee oe 4 2 3 Foam box burn away model enerne 5 2 4 Foam box b rn away results cerei 2 2 5 Insulated Steel Column model 6 2 6 Insulated Steel Column results eese 6 2 1 Water cooling model erreser
20. rees iier e pee eye qiie Re tec eei 7 2 8 Water cooling results e Gee eU eet epe eter rens 7 3 1 Burner fire in this example 8 322 Creating E reget ec eiae sete e a eget ues 9 3 3 Creating new burner surf ce e pee een eet dd 10 3 4 Defining parameters for the burner surface sse 10 3 5 Creating the burn r vent ises ieies ES eaa 11 3 6 After creating the Open Vent dte ette e pente e et Eee ebat b coe be Fee D ects 12 3 7 The model after rotating The burner is shown in red and the top vent in blue 13 3 8 The simulation dialog during the analysis eeee 14 3 9 The initial Smokeview display eeeeeee eee emen 15 3103D smoke in the model rore en ede tne s eae o Yen ehe e bell t ue 15 3 11 Temperature contours on the slice plane 16 3 12 Temperature time history plot ecco e E orat e eti erase 16 4 1 Smoke inthe model 2 eee ee Leere aeree dae epe dene PER 17 4 2 Creating new burner OE Re 18 4 3 Defining parameters for the burner surface sssseeeeee eee 18 4 4 Creating th burner vent Ee 19 4 5 Creating the mesh nere erneut cerae anh pe du Re th ee 20 4 6 Creatine the wall
21. the bottom of the Smoke view window To return to animation mode press t 4 To reset Smokeview right click to activate the menu then click Load Unload gt Unload All Hane il Eu Smokeview 5 0 5 Nov 6 2007 Frame 243 Tme 4190 EREMO jJ Figure 3 10 3D smoke in the model View Temperature Slice Plane 1 In the Smokeview window right click to activate the menu 15 Burner Fire with Tem perature Measurement 2 In the menu click Load Unload gt Slice File gt TEMPERATURE gt Y 0 06667 This will start an animation of the temperature slice plane Note that the Y coordinate of the plane was shifted by FDS to correspond to the center of a cell E ture E CEES Smokeview 5 0 5 Nov 6 2007 Slice Frame 220 Time 3 3 Figure 3 11 Temperature contours on the slice plane View Temperature Measurements 1 In the PyroSim window on the FDS menu click Plot Time History Results 2 A dialog will appear showing the different types of 2D results that are available Select burner_deve csv and click Open to view the temperature device output Export temp 1 5 m 00 200 m E 1000 1200 Time s Figure 3 12 Temperature time history plot 16 Chapter 4 Smoke Layer Height and Heat Flow Through a Door In this tutorial you will simulate an 800 kW fire in the corner of a 5m x 5m room The room has
22. to define solid object in the model In this example we will use an obstruction to define a wall 1 On the Model menu click New Obstruction 2 In the Description box type wal1 Figure 4 6 3 In the Min X box type 0 0 and in the Max X box type 5 0 4 In the Min Y box type 4 0 and in the Max Y box type 4 2 5 In the Min Z box type 0 0 and in the Max Z box type 2 4 6 Click OK to create the wall obstruction Obstruction Properties amp Specification Activation Events Description wall Group Model Specify Color 1 Sawtooth Thicken V Permit Holes E Texture Origin m Relative to object X 0 0 Y 0 0 2 0 0 Bounding Box Min X 0 0 Min Y 4 0 Min Z 0 0 Max X 5 0 MaxY 42 MaxZ 2 4 Surface Properties Single Bert ov Multiple INERT Max X INERT Min Y INERT Max Y INERT Min Z INERT MaxZ INERT Figure 4 6 Creating the wall Add the Door In FDS holes are used to define openings through solid objects In this example we will use a hole to define a door 21 Smoke Layer Height and Heat Flow Through a Door 1 On the Model menu click New Hole 2 In the Description box type door 3 In the Min X box type 2 0 and in the Max X box type 3 0 4 In the Min Y box type 3 9 and in the Max Y box type 4 3 5 In the Min Z box type 0 0 and in the Max Z box type 2
23. 0 6 Click OK to create the doorway hole Rotate the Model for a Better View 1 To reset the zoom and properly center the model press CTRL R PyroSim will now be looking straight down at the model along the Z axis 2 Press the left mouse button button in the 3D View and drag to rotate the model f B YX PyroSim Untitled Eile Edit Model Devices Output FDS View Help 11 4 1 amp 4 b t3 show al Floors ST 3D View 2D View Record View Figure 4 7 The model after rotating The burner is shown in red and the top vent in blue Add a Layer Zoning Device 1 On the Devices menu click New Layer Zoning Device 2 In the Device Name box type 1201 3 For the End Point 1 coordinates in the X box type 2 5 in the Y box type 2 5 and in the Z box type 0 0 22 Smoke Layer Height and Heat Flow Through a Door 4 For the End Point 2 coordinates in the X box type 2 5 in the Y box type 2 5 and in the Z box type 2 4 5 Click OK to create the layer zoning device It will be displayed as a line in the model Add a Flow Measuring Device 1 On the Devices menu click New Flow Measuring Device 2 In the Device Name box type door flow 3 In the Plane list select Y and type 4 0 4 In the Min X box type 2 0 and in the Max X box type 3 0 5 In the Min Z box type 0 0 and in the Max Z b
24. 5 7 The concrete surface The sheet metal is 0 05 in 0 0042 ft 0 0013 m thick To create this surface 1 2 In the Edit Surfaces dialog click In the Surface Name box type Sheet Metal in the Surface Type list select Layered Click OK to close the New Surface dialog Click the Color button to open the Surface Color dialog then select blue and click OK In the Material Layers panel in the Thickness column type 0 0042 ft The material composition can be defined as a mixture Click the Edit button In the Mass Fractioncolumn type 1 0 In the Materialcolumn select Steel Click OK to close the Composition dialog 34 Switchgear Fire Example 6 In the Edit Surfaces dialog click Apply to save the changes The cable is 1 5 in 0 125 ft 0 0381 m thick To create this surface 1 In the Edit Surfaces dialog click New 2 Inthe Surface Name box type Cable in the Surface Type list select Layered Click OK to close the New Surface dialog 3 Click the Color button to open the Surface Color dialog then select a black and click OK 4 In the Material Layers tab in the Backing list select Insulated This will approximate a solid being heated from all sides 5 In the Material Layers panel in the Thickness column type 0 125 ft 6 The material composition can be defined as a mixture Click the Edit button In the Mass Fractioncolumn type 1 0 In the Materialcolumn select Cable Click OK to close t
25. a 1m doorway You will learn how to measure smoke layer height in the compartment and heat flow though the doorway In this tutorial you will Create an 800 kW burner fire Create a doorway using a hole Add a flow measurement device Adda layer zoning device to measure layer height View 3D results using Smokeview View 2D results using PyroSim Voce Ex Smokeview 5 0 5 Nov 6 2007 W171 Frame 600 _ 27 72 Figure 4 1 Smoke in the model Before you begin ensure that you are using SI units see Chapter 1 Create the Burner Surface Surfaces are used to define the properties of objects in your FDS model In this example we define a burner surface that releases heat at a rate of 800 kW m2 1 On the Model menu click Edit Surfaces 2 Click New 3 In the Surface Name box type burner Figure 4 2 17 Smoke Layer Height and Heat Flow Through a Door 4 In the Surface Type list select Burner 5 Click OK to create the new default burner surface New Surface x Surface Name burner Surface Type Burner Template Surface INERT Figure 4 2 Creating a new burner surface 1 In the Description box type 800 kW m2 burner Figure 4 3 2 Click the Color button to open the Surface Color dialog then select a good burner color e g red and click OK 3 In the Heat Release Rate HRR
26. an happen that the small offset will mean that the vent is moved to a different mesh coordinate than the duct An unattached vent will be ignored in the solution so either position the vent directly on the duct or look at the mesh in Smokeview to make sure you see the vent displayed In the Bounds boxes enter the values in Table 5 15 Click OK to close the Vent Properties dialog Table 5 15 Return vent dimensions X ft Z ft Min 13 30 11 0 Max TSQ 13 0 Copy to create the second return vent 1 2 3 4 5 Inthe Navigation View tree on left right click on Return Vent 3B and click Copy Move Click Copy and type 1 in the Number of Copies box In the Offset box for X type 30 5 Click OK This will create Return Vent 3B 1 Double click and change the name to Return Vent 3A To create the supply duct for Room 3B 1 2 3 On the Model menu click New Obstruction In the Description box type Supply Duct In the Group list select Vents Click Specify Color The default gray color does not need to be changed In the Bounding Box boxes enter the values in Table 5 16 Click OK to close the Obstruction Properties dialog 47 Switchgear Fire Example Table 5 16 Supply duct dimensions X ft Y ft Z ft Min 2335 12 20 18 0 25 5 13 9 Add the supply vent to the supply duct in Room 3B 1 On the Mod
27. ch automatically and display a 3D still image of the model Figure 3 9 amp y FDS Simulation burner fds caje Fire Dynamics Simulator FDS Building and Fire Research Laboratory National Institute of Standards and Technology NIST Starting FDS C Program Files PyroSim 2007 fds fds5 exe m Fire Dynamics Simulator Compilation Date Mon 12 Nov 2007 Version 5 0 2 Serial SVN Revision No 977 Job TITLE Job ID string burner Time Step is Simulation Time 0 12 s Time Step Ri Simulation Time 0 24 s Time Step d Simulation Time 0 36 s Time Step 4 Simulation Time 0 48 s Time Step Simulation Time 0 60 8 Time Step 6 Simulation Time 0 71 8 Time Step T Simulation Time 0 80 s Time Sten Simulation Time n BR B 4 m 2 Progress 10 025 10 05 Time Elapsed 0 00 37 Time Remaining 0 00 00 7 Run smokeview when finished Kil Stop Run Smokeview Save Log Figure 3 8 The simulation dialog during the analysis 14 Burner Fire with Tem perature Measurement burner Smokeview 5 0 5 Nov 6 2007 Figure 3 9 The initial Smokeview display View Smoke in 3D 1 In the Smokeview window right click to activate the menu 2 In the menu click Load Unload gt 3D Smoke gt soot mass fraction RLE This will start an animation of the smoke in this model 3 To view a specific time in the animation click the timeline bar in
28. ds5S e Fire Dynamics Simulator Compilation Date Mon 12 Nov 2007 Version 5 0 2 Serial SVN Revision No 977 Job TITLE Job ID string smoke Step Simulation Step Simulation Step Simulation Step Simulation Step Simulation Step Simulation Progress 45 025 45 05 Time Elapsed 0 04 04 Time Remaining 0 00 00 Run smokeview when finished Figure 4 8 The simulation dialog during the analysis smoke Smokeview 5 0 5 Nov 6 2007 Figure 4 9 The initial Smokeview display View Smoke in 3D 1 In the Smokeview window right click to activate the menu 24 Smoke Layer Height and Heat Flow Through a Door 2 In the menu click Load Unload gt 3D Smoke gt soot mass fraction RLE This will start an animation of the smoke in this model 3 In the menu click Load Unload gt 3D Smoke gt HRRPUV RLE This will start add an animation of fire to the model in addition to the smoke 4 To view a specific time in the animation click the timeline bar in the bottom of the Smoke view window To return to animation mode press t 5 To reset Smokeview right click to activate the menu then click Load Unload gt Unload Smokeview 5 0 5 Noy 6 2007 8 171 Frame 600 Time 27 72 nem J Figure 4 10 3D smoke in the model View Time History Data 1 In the PyroSim window on the FDS menu
29. e 425 380 335 290 245 200 155 110 65 0 20 0 mesh 1 M102 kw m3 Frame 554 rine 12 a Figure 5 19 Temperature contours on slice planes at 330 seconds 55 Switchgear Fire Example r E switchgear Smokeview 5 0 5 Nov 6 2007 Frame 439 prime 520 Figure 5 20 Temperature contours on the solid surfaces at 525 seconds To view time history results 1 In the PyroSim window on the FDS menu click Plot Time History Results 2 A dialog will appear showing the different types of 2D results that are available Select switchgear_deve csv and click Open to view the device output The first display will be the layer height in Room 3A Figure 5 21 56 Switchgear Fire Example 1 5 Time History Plots Layer Room 3A gt HEIGHT 0 0 100 0 200 0 300 0 400 0 500 0 600 0 700 0 Time s Figure 5 21 Layer height in room 3A 57 References McGrattan Klein Hostikka and Floyd 2007 Kevin McGrattan Bryan Klein Simo Hastikka and Jason Floyd Fire Dynamics Simulator Version 5 User s Guide July 2007 NIST Building and Fire Research Laboratory Gaithersburg Maryland USA LBNL 43134 U S NRC 2007 Kevin McGrattan Bryan Klein Simo Hastikka and Jason Floyd Verification and Val idation of Selected Fire Models for Nuclear Power Plant Applications May 2007 U S Nuclear R
30. egulatory Commission Office of Regulatory Research Washington DC USA NUREG 1824 EPRI 1011999 Klein 2007 Bryan Klein Switchgear example problem personal communication 2007 National Institute of Standards and Technology Gaithersburg MD USA 58
31. el menu click New Vent 2 3 6 7 In the Description box type Supply Vent 3B In the Group list select Vent CS Inthe Type list select Supply Vent In the Lies in the plane list select Y and type 23 49 This places it just barely outside the duct for visualization but it will be returned to the exact mesh coordinates during solution In the Bounds boxes enter the values in Table 5 17 Click OK to close the Vent Properties dialog Table 5 17 Supply vent dimensions X ft Z ft Min 11 0 11 0 Max 1 30 13 2 Add the supply vent to the wall in Room 3A 1 On the Model menu click New Vent 2 3 4 5 6 In the Description box type Supply Vent 3A In the Group list select Vent CS In the Type list select Supply Vent In the Lies in the plane list select Y and type 28 5 In the Bounds boxes enter the values in Table 5 18 7 Click OK to close the Vent Properties dialog Table 5 18 Return vent dimensions X ft Z ft Min 34 0 11 0 Max 36 0 13 0 48 Switchgear Fire Example An image showing the ducts and vents is given in Figure 5 15 The duct color has been changed to cyan File Edit Model Devices Output FDS View Help D e 2 amp ua 5 EOE Show al Floors E D Wk ES Bg mq Surfaces BB cable
32. en click the Color button to open the Surface Color dialog Select a light blue color and click OK In the Lies in the Plane list select Z and type 3 0 In the Min X box type 1 0 and in the Max X box type 1 0 In the Min Y box type 1 0 and in the Max Y box type 1 0 Click OK to create the open vent 11 Burner Fire with Tem perature Measurement Pyrosim Untitled File Edit Model Devices Output FDS View Help B eig im ia wxcxmcoximiemg x ore ee open top 2D View Record View Figure 3 6 After creating the open vent Rotate the Model for a Better View 1 To reset the zoom and properly center the model press CTRL R PyroSim will now be looking straight down at the model along the Z axis 2 Press the left mouse button button in the 3D View and drag to rotate the model 12 Burner Fire with Tem perature Measurement File Edit Model Devices Output FDS View Help AGH s4 4S A BEX MIAARASH 2 ROAA son mro 9 e open top 4 gt 3D View 2D View Record View Figure 3 7 The model after rotating The burner is shown in red and the top vent in blue Add a Temperature Measurement Device 1 2 On the Devices menu click New Gas Phase Device In the Device Name box type temp 1 5 m In the Qua
33. erial Type list select Solid Click OK to close the New Material dialog 32 Switchgear Fire Example 3 4 2 6 In the Density box type 1380 kg m 3 In the Specific Heat box type 1 289 kJ kg K In the Conductivity box type 0 192 W m K Click OK to save the changes and close the Edit Materials dialog Save the Model This is a good time to save the model 1 2 3 On the File menu click Save Choose a location to save the model Because FDS simulations generate many files and a large amount of data it is a good idea to use a new folder for each simulation For this example we will name the file C Switchgear switchgear psm Click OK to save the model Surface Properties Surfaces are used to define the properties of objects in your model Solid surfaces will use the material properties previously defined Vent and burner will be defined directly without refer ence to materials This problem uses English units as the primary values for the geometry Switch to English units 1 2 On the View menu click Units Select English The concrete wall is 2 ft 0 6096 m thick This will be a Layered surface although we will define only one layer To create this surface 1 2 On the Model menu click Edit Surfaces Click New Inthe Surface Name box type Concrete Wal1 in the Surface Type list select Layered Click OK to close the New Surface dialog Click the Co
34. fire displayed 6 In the Bounds boxes enter the values in Table 5 19 50 Switchgear Fire Example 7 Click OK to close the Vent Properties dialog Table 5 19 Fire dimensions Y ft Z ft Min 20 0 6 5 Max 23 0 0 Teas Smoke Detectors Each room has a smoke detectors In this analysis they will be used to output data but will not activate any features in the model To create the smoke detectors 1 On the Devices menu click New Smoke Detector 2 In the Detector Name box type Room 3B 3 In the Location boxes type 14 0 10 0 and 19 75 4 Click OK to create the detector 5 On the Devices menu click New Smoke Detector 6 In the Detector Name box type Room 3A 7 In the Location boxes type 44 5 10 0 and 19 75 8 Click OK to create the detector Post Processing Controls There are a number of tools provided in PyroSim to instrument the building and determine what is going on at each time step Slice files thermocouples and boundary files are some of the most common instruments We will define a layer device T Layer Zone Device To add a layer zone device 1 On the Devices menu click New Layer Zoning Device 2 In the Device Name box type Layer Room 3A 3 To add the device to Room 3A fill the Path table by entering the values in Table 5 20 4 Click OK to close the Layer Zoning Device dialog Repeat these steps but this time adding a device to Room 3B u
35. havior Surface Surfaces are used to define the properties of solid objects and vents in your FDS model The surface can use previously defined materials in mixtures or layers By default all solid objects and vents are inert with a temperature that is fixed at the initial temperature Before Starting Obstruction Obstructions are the fundamental geometric representation in FDS Obstructions are rectangular solids defined by two points Surface properties are assigned to each face of the obstruction Activation events can be defined to create or remove an obstruction during a simulation The geometry of an obstruction does not need to match the geometry of the mesh used for the solution However the geometry can only be resolved to the mesh At the time of analysis all faces of an obstruction are shifted to correspond to the nearest mesh cell Thus some obstructions may become thicker in the analysis others may become thin and correspond to a single cell face which has the potential to introduce unwanted gaps into a model These ambiguities can be avoided by making all geometry correspond to the mesh spacing Vent Vents have general usage in FDS to describe 2D planar objects Taken literally a vent can be used to model components of the ventilation system in a building like a diffuser or a return In these cases the vent coordinates define a plane forming the boundary of the duct No holes need to be created air is supplied o
36. he Composition dialog 7 Click on the Reaction tab 8 Click to select Governed Manually 9 In the Heat Release Rate box type 265 kW m 2 In the Ignition panel select Ignite at and type 250 C 10 Click OK to save the changes and close the Edit Surfaces dialog Model Geometry We will now create the geometry using a few dialogs and by drawing a few walls If you were working on a more complex building you could display the floor plan in the 2D View and then sketch walls directly on the background image or import the data from a DXF file The model will only include the separating wall between the two rooms There is no need to define the perimeter walls since the perimeter will be defined to have the surface properties of the concrete wall During the creation of a PyroSim model it is recommended that you group the various parts of the building for purposes of editing and later viewing For example all walls will be placed in a sub group called Walls This allows us to quickly select this group to modify it or to hide it for viewing of other interior details The problem dimensions use English units as the primary values To switch to English units On the View menu click Units 2 Select English Walls and Doors To make a new group 35 Switchgear Fire Example 1 On the Model menu click New Group 2 In the Parent Group list select Model 3 In the Group Name box type Walls 4 Click OK to clo
37. hter connection between meshes 0 0 MinZ 00 2 20 0 Cell Size Ratio 1 11 Cell Size Ratio 1 00 Cell Size Ratio 1 05 D Room 3B Click OK to close the rename Click Rename and in the Name box type GR dialog In the Order Priority list select 2 give a cell size of approximately 1 0 ft 0 3048 In the mesh boundary boxes enter the values in Table 5 7 In the X Y and Z cell boxes enter 30 enter 30 and enter 20 respectively These divisions m Click OK to save the data and create the meshes 30 Switchgear Fire Example Table 5 7 Dimensions for the mesh in Room 3B including 2 thick walls X ft Y ft Z ft Min 0 0 0 0 0 0 Max 27 5 28 5 20 0 The meshes are shown in Figure 5 4 On the toolbar click to reset the image Click You can rotate pan and zoom the model using the mouse and the Shift and Alt keys Ele Edit Model Devices Output FDS View Help Beli eiuu owxcnox Im taosrx3 9 ros E amp Record View Figure 5 4 Display of the mesh Material Properties FDS Version 5 uses materials to define physical properties In this model we will include the following material types concrete sheet metal and thermo plastic cable We note that the ma terial properties in the problem description have been provided in metric units so we will tem porarily
38. i iz CEES Smokeview 5 0 5 Nov 6 2007 Slice Frame 220 Time 3 9 Figure 3 1 Burner fire in this example Before you begin ensure that you are using SI units see Chapter 1 Create the Mesh In this example we will use mesh cells that are 0 13 m across This value is approximately 1 5 of the characteristic diameter D for a 500 kW fire As a rule of thumb this is as large as the mesh cells can be while still maintaining a moderate level of accuracy in modeling the plume U S NRC 2007 Using mesh cells that are smaller by a factor of 2 should decrease error by a factor of 4 but will increase the simulation run time by a factor of 16 1 On the Model menu click Edit Meshes 2 Click New Figure 3 2 3 In the Min X box type 1 0 and in the Max X box type 1 0 Burner Fire with Tem perature Measurement 4 In the Min Y box type 1 0 and in the Max Y box type 1 0 5 In the Min Z box type 0 0 and in the Max Z box type 3 0 6 In the X Cells box type 15 7 In the Y Cells box type 15 8 In the Z Cells box type 24 9 Click OK to save changes and close the Edit Meshes dialog Order Priority 1 E Specify Color V Synchronize time step For tighter connection between meshes Mesh Boundary MinX 1 MnY 1 MinZ 0 0 MaxX 1 MaxY 1 2 3 0 Division Method Uniform XCels 15 size Ratio 1 07 YCels 15 Cell s
39. ize Ratio 1 07 ZCels 24 Cell Size Ratio 1 00 Cell Size m 0 13 x 0 13 x 0 12 Number of cells for mesh 5400 Figure 3 2 Creating the mesh Create the Burner Surface Surfaces are used to define the properties of objects in your FDS model In this example we define a burner surface that releases heat at a rate of 500 kW m2 1 On the Model menu click Edit Surfaces 2 Click New 3 In the Surface Name box type burner Figure 3 3 4 In the Surface Type list select Burner 5 Click OK to create the new default burner surface Burner Fire with Tem perature Measurement New Surface Surface Name burner Surface Type Burner 7 Template Surface INERT re Figure 3 3 Creating a new burner surface 1 In the Description box type 500 kW m2 burner Figure 3 4 2 Click the Color button to open the Surface Color dialog then select a good burner color e g red and click OK 3 In the Heat Release Rate HRR box type 500 4 Click OK to save changes and close the Edit Surfaces dialog ADIABATIC Surface ID burner burner INERT MIRROR Color Q OPEN Description Surface Type Burner X Heat Release Particle Injection Heat Release Heat Release Rate HRR 500 0 kwim Mass Loss Rate 0 0 kg m s Ramp Up Time Default 1 0 5 Extinguishing Coefficient 0 0 15 Temperature Surface Temperature
40. j 3 Dividing wall B Entrance Door Vent amp Entrance Door Block EN 30 View view Record View Figure 5 10 Sketch of the lower left cabinet By default the cabinet sketch snapped to the sketch grid points To precisely define the dimen sions of the cabinet 1 In the 2D View action toolbar top of window click the Select and Manipulate Objects tool 2 Double click on the cabinet to edit its properties 3 In the Description box type Cabinet 1 4 In the Bounding Box boxes enter the values in Table 5 11 5 Click OK to close the Obstruction Properties dialog Table 5 11 Cabinet Dimensions X ft Y ft Z ft Min 4 0 4 0 0 0 Max 20 0 10 0 8 0 We will now copy the first cabinet using the Translate Objects tool in the 2D View l Using the Select and Manipulate Objects tool k click on Cabinet 1 2 Click the Translate Objects tool 40 Switchgear Fire Example 3 Press the CTRL key to create a copy and drag the vertical handle to create a second cabinet located symmetrically relative to Cabinet 1 Figure 5 11 4 Click the Select and Manipulate Objects tool k 5 Double click on the new cabinet and change the name to Cabinet 2 The dimensions for Cabinet 2 are given in Table 5 12 Eile Edit Model Devices Output FDS View Help B eig emiuiOwx amp mb5x iz nam REA a
41. l is shown in Figure 2 3 A typical result is shown in Figure 2 4 Example Problems Provided with FDS 5 a YX PyroSim C Examples Box Away box bum awaypsm Ste Eie Edi Model Devices Output FDS View Help BeoG aa St ROX MAAK 66 Em xXx eam Smokeview 5 0 7 Dec 30 2007 Slice 8 571 kw ma Figure 2 4 Foam box burn away results Insulated Steel Column The insulated steel column fds example illustrates heat conduction into a column The model is shown in Figure 2 5 A typical result is shown in Figure 2 6 Example Problems Provided with FDS 5 YX PyroSim C Examples Insulated Steel Column insulated_steel_column psm Edit Model Devices Output FDS View Help 5 4 EAE o JEB amp E15 Materials INSULATION STEEL 8 6 surtaces B ffl mert MRROR f OPEN THICKLY INSULATED COLUMN EXT 2 THICKLY INSULATED COLUMN INT Devices Temp_ext 10 1 Temp_ext_JOR 1 gt Temp_ins_lOR 1 t Temp ins IOR 1 t Temp int IOR2 1 Temp int IOR 1 Ei dib Model Grid Boundary Vents Obstruction 1 f obstruction 2 f obstruction 3 obstruction 4 Lo obstruction 5 20 View Record View Figure 2 5 Insulated Steel Column m
42. lick the Color button to open the Surface Color dialog then select red and click OK 3 Select Heat Release Rate box and type 3000 0 kW m 2 Note that this value is the HRR per unit area This corresponds to a peak HRR of 834 kW total distributed over an area of 3 0 square feet 0 278 square meters 4 In the Ramp up Time list select T2 and type a value of 60 s This means the fire will ramp up over 60 seconds to the peak value 5 Click OK to close the Edit Surfaces dialog Switch back to English units to define the geometry On the View menu click Units 2 Select English To add the fire to the top of the cabinet 1 On the Model menu click New Vent 2 In the Description box type Fire 3 In the Group list select Fire 4 In the Type list select Fire 5 In the Lies in the plane list select X and type 50 51 This places it just barely outside the cabinet for visualization but it will be returned to the exact mesh coordinates during solution To repeat a word of caution In most cases this slight offset will not cause any problem since both the vent fire and cabinet will be moved to the same mesh coordinates during the solution However it can happen that the small offset will mean that the vent is moved to a different mesh coordinate than the cabinet An unattached vent will be ignored in the solution so either position the vent directly on the cabinet or look at the mesh in Smokeview to make sure you see the vent
43. list select Concrete Wall 3 Click OK to close the Simulation Parameters dialog Run the Analysis Your model should now look like Figure 5 17 Save the model To run the analysis 1 On the FDS menu click Run FDS 53 Switchgear Fire Example XK PyroSim C Switchgear switchgear ps File Edit Model Devices Output FDS View Help a B OLS stom E Oh 9 4 OB E Entrance Door Vent Entrance Door Bloch amp Switchgear cabinet 1 cabinet 2 cabinet 3 cabinet 4 fh Cables Vents g Supply Duct E supply Vent E supply Vent E Return vent E Return vent 5 4 Fire Fire m TI it mm 2D View Record View m Figure 5 17 Completed model View the Results You can use the SmokeView software to make plots of the results An image showing the smoke density is shown in Figure 5 18 An image showing the temperature contours on the slice planes is shown in Figure 5 19 An image showing the temperature contours on the surfaces is shown in Figure 5 20 54 Switchgear Fire Example r switchgear 2g Smokeview 5 0 5 Nov 6 2007 mesh 1 E3102 wma Frame 175 BENE DJ Figure 5 18 Smoke in rooms at 105 seconds Smokeview 5 0 5 Nov 6 2007 Slic
44. lor button to open the Surface Color dialog then select a dark gray and click OK In the Material Layers panel in the Thickness column type 2 0 ft The material composition can be defined as a mixture Click the Edit button In the Mass Fractioncolumn type 1 0 In the Materialcolumn select Concrete Figure 5 6 Click OK to close the Composition dialog In the Edit Surfaces dialog click Apply to save the changes Figure 5 7 33 Switchgear Fire Example R Composition x Mass Fraction Material El Insert Row 1 1 0 Concrete E Remove Row A Move Up 42 Move Down Copy Paste Cut Figure 5 6 Composition of the concrete surface Surfaces ADIABATIC SurfaceID Concrete Wall pue Description INERT Color l Texture MIRROR OPEN Surface Type Layered Sheet Metal Material Layers Reaction Species Injection Particle Injection H Initial Internal Temperature TMPA F Backing Air Gap Default Gap Temperature PE Temperature Ramp Default 1 0 5 Material Layers Thickness Ft Material Composition Edit Insert Row 1 2 0 1 0 Concrete Gaz E Remove Row A Move Up MoveDown mun Is Copy From bran Q Paste Rename Cut Delete f Apply Cancel Figure
45. mesh in Room including 2 thick walls 31 5 8 Dividing wall dimension S siesena nnne 36 5 9 Dividing door dimensions eese hehehe 37 5 10 Entrance door blockage dimensions eeeeeeeeeeeeeeeeene een 38 SALT Cabinet Dimensions eere mee reden ere edet ere en eese 40 5 12 Dimensions for Cabinet 9 E EA E 41 5 13 A DIMENSIONS 5 43 2 14 Cable Dimensiotns Ere aael aies 44 5 157 Return Vent dimensions esr 5 e erre ER Ae rarest tebe 47 5 16 Supply duct dimensions fe ee E dee PEL idee Lente Pa nda etd 48 5 17 Supply vent dimensions eet rient d ite ni ine 48 5 185 Return vent dimensions see inerte eee ee ntt coven End eee een Nee 48 S19 Fire dimension Sie ninenin geen eer eoe eene He een ee INE doko e Pe e tend ded 51 3 20 Layer data for Room 3 5 2 4 12 vous s An AN ee eng d elon ne e 52 5 21 Layer data for Room ssir iiie eiT ESE esia ri Eg KeS 52 5 22 Slice plane e oap eei pea eee ee a E ota E aet 52 viii Chapter 1 Before Starting Install PyroSim In order to work through this tutorial you must be able to run PyroSim You can download PyroSim from the inte
46. n of the switchgear room complex showing switchgear cabinets cable trays supply ducts and vents and smoke detectors Drawing not to scale This tutorial demonstrates how to Define materials Create and replicate geometry Open doors after a specified time Create a burner fire Add a smoke layer device Adda slice plane for temperature visualization View 3D results using Smokeview View 2D results using PyroSim 27 Switchgear Fire Example YK PyroSim C Switchgear switchgear ps File Edit Model Devices Output FDS View Help amp eg miu wcmsximie ax lI sron B x amp amp B amp fB Surfaces OB Cable E Entrance Door Vent Entrance Door amp Switchgear cabinet 1 cabinet 2 cabinet cabinet 4 fh Cables E dib Vents g Supply Duct Supply Vent E supply Vent E Return vent E Return vent Fire Bg Fire m Iam 2D View Record View Figure 5 2 Completed model Model parameters are given below Table 5 1 Room size interior dimensions Dimension English Metric Length 28 6 8 6m Width 28 6 8 6m Height 20 6 0m Wall Thickness 2 0 6096 m Table 5 2 Door size Dimension English Metric Width 3 0 9m Height 8 24
47. nits On the View menu click Units 2 Select English To create the first solution mesh for Room 3A 1 On the Model menu click Edit Meshes 2 Click New to create a mesh 3 Click Rename and in the Name box type Room 3A Click OK to close the rename dialog 4 In the Order Priority list select 1 This ensures that the finer mesh is the primary mesh for the solution 5 In the mesh boundary boxes enter the values in Table 5 6 6 In the X Y and Z cell boxes enter 60 enter 60 and enter 40 respectively as shown in Figure 5 3 The FDS solution is optimized when the mesh cell division is defined by a number 29 Switchgear Fire Example that can be formed using multiples of powers of approximately 0 5 ft 0 1524 7 Click Apply to create the mesh of 2 3 and 5 These divisions give a cell size Table 5 6 Dimensions for the mesh in Room 3A including 2 thick walls X ft Y ft Z ft Min 27 5 0 0 0 0 Max 59 0 28 5 20 0 Edit Meshes order Prionty 15 E Specify Colo Mesh Boundary ft MinX 275 59 0 Division Method Uniform XCels 60 YCels 60 ZCels 40 Cell Size ft 0 52 x 0 48 x 0 50 Number of cells For mesh 144000 Figure 5 3 Input to create the mesh To create the second solution mesh for Room 3B Click New to create a mesh Min Y MaxY 285 V Synchronize time step for tig
48. ntity list select Temperature On the Location row in the Z box type 1 5 Click OK to create the temperature measurement device It will appear as a yellow dot in the center of the model Add a Temperature Slice Plane 1 2 On the Output menu click Slices In the XYZ column click the cell and select Y In the Plane Value column click the cell and type 0 0 In the Gas Phase Quantity column click the cell and select Temperature In the Use Vector column click the cell and select NO Click OK to create the slice plane 13 Burner Fire with Tem perature Measurement Save the Model On File menu click Save Choose a location to save the model Because FDS simulations generate many files and a large amount of data it is a good idea to use a new folder for each simulation For this example we will name the file c Burner burner psm Click OK to save the model Run the Simulation On the FDS menu click Run FDS Choose a location to save simulation data For this example we will name the file c NBurn er burner fds Click OK to save the FDS input file and begin the simulation The FDS Simulation dialog will appear and display the progress of the simulation By default PyroSim specifies a 10 second simulation This should take approximately 1 minute to run depending on computing hardware Figure 3 8 When the simulation is complete Smokeview should laun
49. o add records to the Additional Records section and the simulation is unaffected How ever if records are dropped i e omitted from the simulation the simulation results will no longer represent the original intent of the example problem Ethanol Pan Fire The ethanol_pan fds example illustrates an ethanol pan fire The model is shown in Figure 2 1 A typical result is shown in Figure 2 2 Example Problems Provided with FDS 5 YR PyroSim C Examples Ethanol Pan ethanol_pan psm File Edit Model Devices Output FDS View Help Be gjmi cw moximie En ron ros 5 6 surfaces B ff ETHANOL POOL mert mirror B open ffl STEEL SHEET Devices tburn rate con flux heat flux flux temp 0 mm temp 1 mm t temp 2 mm ttemp 3 mm ttemp 4 mm ttemp 5 mm ttemp 6 mm ttemp 7 mm _ al Grid Boundary a f 00 obstruction 1 obstruction 2 ff Obstruction 3 obstruction 4 f obstruction 5 BL vent El vent 2 Vent 3 B Vent 4 3D View 2D View Record View Figure 2 1 Ethanol pan model l a ethanol e 7 1 Smokeview 5 0 7 Dec 30 2007 8 571 kw m3 iFrame 20 meo DE Figure 2 2 Ethanol pan results Box Burn Away The box_burn_away fds example illustrates burning of a foam box The mode
50. odel r soo co ec Smokeview 5 0 7 Dec 30 2007 Bndry Slice temp temp 1020 545 920 510 820 475 720 440 620 405 520 370 420 335 320 300 220 265 120 230 20 0 195 Frame 566 ine 10135 M Figure 2 6 Insulated Steel Column results Water Cooling The water_cooling fds example illustrates water cooling spray onto a wall The model is shown in Figure 2 7 A typical result is shown in Figure 2 8 Example Problems Provided with FDS 5 5 b e d ease K PyroSim Untitled lo 8 File Edit Model Devices Output FDS View Help De OMGE shon alt Fors ED Grid Boundary Vent CUL 30 View 2D View Record View Bndry Slice temp temp 180 285 165 275 150 265 135 255 120 245 105 235 900 225 750 215 600 205 450 195 300 185 Figure 2 8 Water cooling results Chapter 3 Burner Fire with Temperature Measurement In this tutorial you will create a 500 kW burner fire and measure the temperature in the center of the plume at a height of 1 5 m This tutorial demonstrates how to Create a burner fire Add a temperature measurement device Adda slice plane for temperature visualization View 3D results using Smokeview View 2D results using PyroSim E
51. ox type 2 0 6 Click OK to create the flow measuring device It will appear as a yellow plane in the model Set the Simulation Length 1 On the FDS menu click Simulation Parameters 2 On the Time panel in the End Time box type 45 0 3 Click OK to save the simulation parameters Save the model 1 On the File menu click Save 2 Choose a location to save the model Because FDS simulations generate many files and a large amount of data it is a good idea to use a new folder for each simulation For this example we will name the c Smoke smoke psm 3 Click OK to save the model Run the Simulation 1 On the FDS menu click Run FDS 2 Choose a location to save simulation data For this example we will name the file c Smoke smoke fds 3 Click OK to save the FDS input file and begin the simulation 4 The FDS Simulation dialog will appear and display the progress of the simulation By default PyroSim specifies a 10 second simulation This should take approximately 1 minute to run depending on computing hardware Figure 4 8 23 Smoke Layer Height and Heat Flow Through a Door 5 When the simulation is complete Smokeview should launch automatically and display a 3D still image of the model Figure 4 9 Cee el Fire Dynamics Simulator FDS Building and Fire Research Laboratory National Institute of Standards and Technology NIST Starting FDS C Program Files PyroSim 2007 fds f
52. r exhausted by the vent You can also use vents as a means of applying a particular boundary condition to a rectangular patch on a surface A fire for example can be created by specifying a vent on either a mesh boundary or solid surface The vent surface defines the desired characteristics of fire Computational Mesh FDS calculations are performed within a domain made of rectilinear volumes called meshes Each mesh is divided into rectangular cells Two factors that must be considered when choosing the cell size are the required resolution to define objects in the model obstructions and the desired resolution for the flow dynamics solution including local fire induced effects Although geometric objects obstructions in an FDS analysis can be specified using dimensions that do not fall on cell coordinates during the FDS solution all faces of an obstruction are shifted to the closest grid cell If an obstruction is very thin the two faces may be approximated on the same cell face The FDS Users Guide McGrattan Klein Hostikka and Floyd 2007 recommends that for full functionality obstructions should be specified to be at least one grid cell thick As a result the cell size must be selected small enough to reasonably represent the problem geometry In addition cells should be as close to cubes as possible Whether the cell size is sufficient to resolve the flow dynamics solution can only be determined by a grid sensitivity study A di
53. rnet by going to http www pyrosim com to obtain the free trial Units Except where noted the instructions given in this tutorial will assume that PyroSim s current unit system is SI If PyroSim is using a different unit system the simulation will not produce the expected results To ensure that you are using SI units 1 In the View menu click Units 2 In the Units sub menu verify that SI is selected At any time you can switch between SI and English units The data is stored once in the original system so there is no loss of accuracy when you switch units Manipulating the 3D Image To spin the 3D model select then left click on the model and move the mouse The model will spin as though you have selected a point on a sphere To zoom select or hold the ALT key and drag the mouse vertically Select then click and drag to define a zoom box To move the model select or hold the SHIFT key and drag to reposition the model in the window To change the focus of the view select an object s and then select ES to define a smaller viewing sphere around the selected objects Selecting will reset the view to include the entire model At any time selecting or pressing CTRL R will reset the model You can also use Smokeview and person oriented controls See the PyroSim User Manual for instructions FDS Concepts and Nomenclature Material Materials are used to define thermal properties and pyrolysis be
54. scussion of model sensitivity to mesh size is given in Chapter 5 of Verification and Validation of Selected Fire Models for Nuclear Power Plant Applications U S NRC 2007 It is the responsibility of the analyst to perform a sensitivity study as part of any simulation Chapter 2 Example Problems Provided with FDS 5 If you want to have fun and quickly run some example analyses you can import FDS 5 input files that are included with the NIST installation of FDS 5 These examples are provided with the PyroSim distribution in the PyroSim 2007 samples FDS5 folder In this chapter we illustrate this using a few examples you can import additional examples Studying these examples is a good way to learn about input for different types of analyses To open any of these examples 1 Obtain the desired FDS 5 input file 2 Start PyroSim 3 On the File menu click Import and select FDS File 4 In the Open File dialog click the FDS input file PyroSim will import the file PyroSim will warn if any records on the FDS file cannot be imported 5 On the File menu click Save Save the model in a new directory 6 On the FDS menu click Run FDS This will start the analysis At the end of the analysis SmokeView will be launched to view the results Important If PyroSim doesn t fully support a FDS input file it will issue a warning that includes information about how it handled the unfamiliar records In some cases PyroSim is able t
55. se the Create Group dialog To define the dividing wall 1 On the Model menu click New Obstruction 2 In the Description box type Dividing Wall 3 In the Group list select Walls 4 In the Bounding Box boxes enter the values in Table 5 8 Figure 5 8 5 In the Surface Properties panel select Single and select Concrete Wall from the list 6 Click OK to close the Obstruction Properties dialog 7 On the View menu click un select the Show Grids option The display should now look like Figure 5 9 Table 5 8 Dividing wall dimensions X ft Y ft Z ft Min 28 5 0 0 0 0 Max 30 5 28 5 20 0 Obstruction Properties Specification Activation Events Description Group 7 Specify Color Dividing Wall amp Wals ps V Sawtooth Thicken V Permit Holes Texture Origin Ft Z Relative to object 00 Bounding Box ft Min X 28 5 MaxX 305 Surface Properties Single B concrete wall inert Y Inert inert Figure 5 8 Input for the wall dividing the two rooms 36 Switchgear Fire Example PyreSim CASwitehgeanewitchgearpem ote ile Edit Model Devices Output FDS View Help amp 9 4 ELA SA 166 5 A amp Concrete Sheet Metal 5 6 Surfaces B Cable P a Concrete Wall
56. sing the data in Table 5 21 51 Switchgear Fire Example Table 5 20 Layer data for Room 3A X ft Y ft Z ft End Point 1 ft 44 25 14 25 1 0 End Point 2 ft 44 25 14 25 19 0 Table 5 21 Layer data for Room 3B X ft Y ft Z ft End Point 1 ft 14 25 14 25 1 0 End Point 2 ft 14 25 14 25 19 40 Slice Planes Slice planes can be used to display 2D contours in the Smokeview display of the results In this analysis we will save temperature data for future plotting We will define a slice plane through the center of the room and the fire To define the slice planes 1 On the Output menu click Slices 2 Fill the table by entering the values in Table 5 22 You can click on the row number to select entire rows to copy and paste speeding the entry 3 Click OK to close the Animated Planar Slices dialog Table 5 22 Slice plane data XYZ Plane Plane Val Gas Phase Quantity Use Vec ue ft tor Y 14 25 ft Temperature NO Y aira Temperature ft NO Z 19 0 ft Temperature NO Boundary Surface Plots Temperatures and other quantities on the surface of objects can be plotted by selecting Surface Plots To define the surface plots 1 On the Output menu click Boundary Quantities 2 Click the Wall Temperature checkbox 3 Click OK to close the Animated Boundary Quantities dialog Isosurfaces
57. switch to metric units 1 On the View menu click Units 2 Select SI To add the concrete to our model 1 On the Model menu click Edit Materials 2 Click New 31 Switchgear Fire Example In the Material Name box type Concrete in the Material Type list select Solid Click OK to close the New Material dialog In the Density box type 2400 kg m 3 In the Specific Heat box type 0 75 kJ kg K In the Conductivity box type 1 6 W m K Click Apply to save the changes Figure 5 5 Edit Materials Material ID Concrete Description Material Type Solid Thermal Properties Pyrolysis Density 2400 kg m Specific Heat Constant x 10 Conductivity Constant 0 1 Wl m K Emissivity 0 9 Absorption Coefficient 5 0 04 ifm New Add From Library Rename Delete Figure 5 5 Concrete properties To add steel 1 2 3 6 In the Edit Materials dialog click New In the Material Name box type St ee1 in the Material Type list select Solid Click OK to close the New Material dialog In the Density box type 7850 kg m 3 In the Specific Heat box type 0 45 kJ kg K In the Conductivity box type 46 6 W m K Click Apply to save the changes The cables will be represented as a thermo plastic material 1 2 In the Edit Materials dialog click New In the Material Name box type Cable in the Mat
58. type Switchgear Click OK to close the Create Group dialog We could define the cabinets using the New Obstruction menu and dialog as described above Instead we will sketch the cabinets To prepare to draw the switchgear cabinets 1 9 Click 2D View Onthe View menu click Select Grid and select the Sketch Grid The Sketch Grid allows you to specify a grid spacing that is useful for creating geometry independent of the solution meshes On the View menu click Set Sketch Grid Spacing In the Snap Spacing box type 0 5 Click OK to close the Snap to Grid dialog In the 2D View drawing tools toolbar left of window click the Draw an Obstruction tool 2 To set the tool properties click Tool Properties 8 In the Min Z box type 0 0 and in the Max Z box type 8 0 In the Surface Prop list select Sheet Metal Click OK to close the New Obstruction Properties dialog In the 2D View action toolbar top of window select Switchgear in the Group list To draw the cabinet 1 2 Press and drag the mouse approximating the dimensions of the lower left cabinet shown in Figure 5 1 Your sketch will approximate that shown in Figure 5 10 39 Switchgear Fire Example PyroSim C Switchgear switchgear ps File Edit Model Devices Output FDS View Help B eil eiaew amp ax iz amp m a RS gt Guess show JED DDE A e E crop g t t
59. undaries 41 5 12 The rooms showing the switchgear cabinets 2 0 0 0 eee eeeeeecececececeeeeeeeeeceeeeeeeeeens 42 vi Example Guide 5 13 5 14 5 15 5 16 5 17 5 18 5 19 5 20 5 21 The room showing the cables eese ee e eee 45 Creating the supply vent surface tee 46 The room showing the vents I e eee eene 49 Defining the temperature isosurfaces 53 Completed model eir e rrt etate e three oed 54 Smoke in rooms at 105 seconds eo iie e ee enden te P 55 Temperature contours on slice planes at 330 seconds 55 Temperature contours on the solid surfaces at 525 seconds 56 Layer height 11 Laine ete rore eee erre eret E 57 vii List of Tables 5 1 Room size interior dimensions ria ET ORR 28 29 2 S126 t 28 5 3 Concrete properties NUREG CR 1805 28 5 4 Sheet metal properties generic esses eene 29 5 5 Cable properties NUREG CR 6850 29 5 6 Dimensions for the mesh in Room including 2 thick walls 30 5 7 Dimensions for the
60. up 2 In the Parent Group list select Model 3 In the Group Name box type Vents 4 Click OK to close the Create Group dialog There are three steps to defining a vent First a surface will be created that defines the flow boundary conditions Next an obstruction is created Finally the vent using the vent surface is attached to the obstruction We will assume all vents are 24 x24 2 x2 For the supply vents we will define a flow rate For the return vents we will just have the vents open to the atmosphere This ensures that the air pressure in the room is not affected by any difference between supply and return flow rates 45 Switchgear Fire Example To create the surface that represents air supply 1 2 3 4 5 On the Model menu click Edit Surfaces In the Edit Surfaces dialog click New In the Surface Name box type Supply Vent Select Surface Type and in the list select Supply Click OK to close the New Surface dialog To change the properties of the Supply Vent 1 2 In the Edit Surfaces dialog click to select Supply Vent Click the Color button to open the Surface Color dialog then select a yellow and click OK On the Air Flow tab click Specify Velocity and type 8 33 ft s Figure 5 14 This corresponds to 2000 CFM flow through a 2 x2 duct Edit Surfaces ADIABATIC Cable Concrete Wall Fire INERT MIRROR OPEN Sheet Metal
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