Fire Simulation for Engineers/FDS/Parking Lot
Appearance
A simple car parking
[edit | edit source]Description
[edit | edit source]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.
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
[edit | edit source]!!! 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