Fire Simulation for Engineers/FDS/Parking Lot

A simple car parking

Description

In Figure [fig:Car-parking-plan] a simple case of a fire in a car parking is proposed. The data are for demonstration only, and the proposed solution is only one of the many possible solutions.

Drawing of car parking

The objectives of the analysis are:

• Study the critical times for evacuation and rescue operations from fire brigade of the car parking.

• Obtain adiabatic surface temperature to predict the mechanical response of the structure.

The following input file is called car_parking.fds, and it is deeply commented.

Input file and results

 !!! General configuration&HEAD CHID='car_parking',
     TITLE='Covered car parking (10 cars)' / 
     Name of the case and a brief explanation. 
 &TIME T_END=3600.0 / 
     The simulation ends at 3600 seconds. 
 &MISC SURF_DEFAULT='wall', CO_PRODUCTION=.TRUE. / 
     All bounding surfaces have a 'wall' boundary condition
     unless otherwise specified.
     Calculation of formation and destruction of CO at elevated
     temperatures activated. 
 &REAC ID='polyurethane', SOOT_YIELD=0.1875, CO_YIELD=0.02775,
     C=1.0, H=1.75, O=0.25, N=0.065,
     HEAT_OF_COMBUSTION=25300., IDEAL=.TRUE. / 
     Gas phase reaction: polyurethane flexible foam (means) from
     Tewarson SFPE Handbook 3rd ed,
     SFPE handbook table 3-4.14, p. 3-112.

 !!! Computational domain
 &MESH IJK=32,30,10, XB= 0.0, 8.5, 0.5, 8.5, 0.0,2.4 / 
 &MESH IJK=32,30,10, XB=-8.5, 0.0, 0.5, 8.5, 0.0,2.4 / 
 &MESH IJK=32,30,10, XB= 0.0, 8.5,-7.5, 0.5, 0.0,2.4 / 
 &MESH IJK=32,30,10, XB=-8.5, 0.0,-7.5, 0.5, 0.0,2.4 / 
     Four connected calculation meshes and their cells numbers,
     total 38400 cells.

 !!! Properties
 ! Walls 
 &MATL ID='gypsum plaster', CONDUCTIVITY=0.48,
     SPECIFIC_HEAT=0.84, DENSITY=1440. / 
     Thermo-physical properties of gypsum plaster. 
 &SURF ID='wall', COLOR='BRICK', MATL_ID='gypsum plaster',
     THICKNESS=0.03 / 
     Type of boundary condition for walls.
 ! Cars 
 Burning surface of the car: (4 + 2 + 4 + 2) * 1.3 + 4 * 2 = 23.6 m2 
 HRR max for a car: 5000 kW, HRR ramps up in 600 s 
 HRRPUA: 5000 / 23.6 = 211.86 kW/m2 (approx: whole car burns)
 &SURF ID='first_car', HRRPUA=211.86, TAU_Q=-600, COLOR='FLESH' / 
     Type of boundary conditions for the first burning car, a burner. 
 &MATL ID='car_mat', CONDUCTIVITY=54.0,
     SPECIFIC_HEAT=0.465, DENSITY=7850.0 /
     Properties for steel taken from NUREG-1805 pg. 2-11 
 &SURF ID='car', MATL_ID='car_mat', HRRPUA=211.86, TAU_Q=-600,
     IGNITION_TEMPERATURE=250., THICKNESS=0.005,
     BACKING='INSULATED', COLOR='DARK OLIVE GREEN 1' / 
     Type of boundary conditions for other cars.

 !!! Solid geometry
 &OBST XB=  7.5 , 7.75,-7.5, 7.5 ,0.0, 2.4 / E wall 
 &OBST XB= -7.5 ,-7.75,-7.5, 7.5 ,0.0, 2.4 / W wall 
 &OBST XB= -7.75, 7.75, 7.5, 7.75,0.0, 2.4 / N wall 
 &HOLE XB= -1.5 , 1.5 , 7.0, 8.0 ,0.0, 2.0 / N entrance 
     The entrance is open since the beginning. 
 &HOLE XB= 7.0 , 8.0 , 2.0, 7.0 ,2.0, 2.2, COLOR='PALE GREEN',
     DEVC_ID='NE_broke', TRANSPARENCY=.6 / NE window 
 &HOLE XB= -7.0 ,-8.0 , 2.0, 7.0 ,2.0, 2.2, COLOR='PALE GREEN',
     DEVC_ID='NW_broke', TRANSPARENCY=.6 / NW window 
 &HOLE XB= 7.0 , 8.0 ,-2.0,-7.0 ,2.0, 2.2, COLOR='PALE GREEN',
     DEVC_ID='SE_broke', TRANSPARENCY=.6 / SE window 
 &HOLE XB= -7.0 ,-8.0 ,-2.0,-7.0 ,2.0, 2.2, COLOR='PALE GREEN',
     DEVC_ID='SW_broke', TRANSPARENCY=.6 / SW window 
     Window panes are broken by temperature. 
 &VENT XB= -7.5 , 7.5 ,-7.5, 7.5 ,2.4, 2.4, SURF_ID='wall' / soffit 
 &VENT PBX= 8.5 , SURF_ID='OPEN' / E opening 
 &VENT PBX=-8.5 , SURF_ID='OPEN' / W opening 
 &VENT PBY= 8.5 , SURF_ID='OPEN' / N opening 
 &VENT PBZ= 2.4 , SURF_ID='OPEN' / top opening 
     Domain borders are open. 
 &OBST XB= 3.0 , 7.0 , 5.0, 7.0 ,0.2, 1.5, SURF_ID='car' / +E2 car 
 &OBST XB= 3.0 , 7.0 , 2.0, 4.0 ,0.2, 1.5, SURF_ID='car' / +E1 car 
 &OBST XB= 3.0 , 7.0 , -1.6, 0.4 ,0.2, 1.5, SURF_ID='car' / E0 car,
     Asymmetric parking 
 &OBST XB= 3.0 , 7.0 , -2.0,-4.0 ,0.2, 1.5,
     SURF_IDS='first_car','first_car','car' / -E1 car 
 &OBST XB= 3.0 , 7.0 , -5.0,-7.0 ,0.2, 1.5, SURF_ID='car' / -E2 car 
 &OBST XB=-3.0 ,-7.0 , 5.0, 7.0 ,0.2, 1.5, SURF_ID='car' / +W2 car 
 &OBST XB=-3.0 ,-7.0 , 2.0, 4.0 ,0.2, 1.5, SURF_ID='car' / +W1 car 
 &OBST XB=-3.0 ,-7.0 , -1.0, 1.0 ,0.2, 1.5, SURF_ID='car' / W0 car 
 &OBST XB=-3.0 ,-7.0 , -2.0,-4.0 ,0.2, 1.5, SURF_ID='car' / -W1 car 
 &OBST XB=-3.0 ,-7.0 , -5.0,-7.0 ,0.2, 1.5, SURF_ID='car' / -W2 car

 !!! Control logic
 &DEVC ID='NE_broke', XYZ= 7.0, 4.5, 2.1,
     QUANTITY='TEMPERATURE', SETPOINT=300. /
 &DEVC ID='NW_broke', XYZ=-7.0, 4.5, 2.1,
     QUANTITY='TEMPERATURE', SETPOINT=300. /
 &DEVC ID='SE_broke', XYZ= 7.0,-4.5, 2.1,
     QUANTITY='TEMPERATURE', SETPOINT=300. /
 &DEVC ID='SW_broke', XYZ=-7.0,-4.5, 2.1,
     QUANTITY='TEMPERATURE', SETPOINT=300. /
     These devices effectively break window panes at 300 °C.

 !!! Output
 &DEVC XYZ=0.1,0,2.39, QUANTITY='THERMOCOUPLE', ID='2.4' / 
 &DEVC XYZ=0.1,0,2.0 , QUANTITY='THERMOCOUPLE', ID='2.0' / 
 &DEVC XYZ=0.1,0,1.6 , QUANTITY='THERMOCOUPLE', ID='1.6' / 
 &DEVC XYZ=0.1,0,1.2 , QUANTITY='THERMOCOUPLE', ID='1.2' / 
 &DEVC XYZ=0.1,0, .8 , QUANTITY='THERMOCOUPLE', ID='0.8' / 
 &DEVC XYZ=0.1,0, .4 , QUANTITY='THERMOCOUPLE', ID='0.4' / 
     Thermocouples. 
 &DEVC XYZ=0.1,0,2.0 , QUANTITY='FED', ID='FED' / 
     FED calculation. 
 &DEVC XB=0.1,0.1,0,0,0.0,2.4,
     QUANTITY='LAYER HEIGHT', ID='layer_h' / 
     Layer height calculation. 
 &ISOF QUANTITY='TEMPERATURE', VALUE(1)=60.0 / 
     3D contours of temperature at 60 °C. 
 &ISOF QUANTITY='VISIBILITY', VALUE(1)=10.0 / 
     3D contours of VISIBILITY 10 m. 
 &SLCF PBX= 0.1, QUANTITY='TEMPERATURE', VECTOR=.TRUE. / 
 &SLCF PBY= -3., QUANTITY='TEMPERATURE', VECTOR=.TRUE. / 
     Vector slices colored by temperature. 
 &SLCF PBX= 0.1, QUANTITY='VISIBILITY' / 
 &SLCF PBZ= 2.0, QUANTITY='VISIBILITY' / 
     Visibility slices. 
 &SLCF PBX= 0.1, QUANTITY='VOLUME FRACTION',
     SPEC_ID='carbon monoxide' / 
 &SLCF PBX= 0.1, QUANTITY='VOLUME FRACTION',
     SPEC_ID='carbon dioxide' / 
 &SLCF PBX= 0.1, QUANTITY='VOLUME FRACTION',
     SPEC_ID='oxygen' / 
     species slices. 
 &BNDF QUANTITY='WALL TEMPERATURE' / 
 &BNDF QUANTITY='NET HEAT FLUX' / 
 &BNDF QUANTITY='ADIABATIC SURFACE TEMPERATURE' / 
     Quantities at all solid obstructions.
 &TAIL / end of file
Geometry of car parking
Heat release rate in car parking
Thermocouples in a car parking
Windows in a car parking
Car parking FED
Car parking layer height
Car parking AST
Car parking visibility
Car parking visibility isosurfaces
Car parking heat flux
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