PhD Thesis - staffweb - University of Greenwich

APPENDIX 1 : SMARTFIRE VERIFICATION AND VALIDATION REPORT3.3 Simulations for LPC-RUN-007.This test case arises from a fire test conducted by the Loss Prevention Council (LPC) [9].The test is a burning wood crib within an enclosure with a single opening. The testcompartment is illustrated below in Figure 33 and Figure 34 and had a floor area of 6m x4m and a 3.3m high ceiling. The compartment contained a door (vent) measuring 1.0m x1.8m located on the rear 6m x 3.3m wall. The walls and ceiling of the compartment weremade of fire resistant board (Asbestos) which were 0.1m thick.3.3m2.1m6.0m1.8mVENTFIRE3.3mFIREobstructionVent here1.3m 1.1m 1.75m2.5m 1.0mFigure 33 - Front view of LPC 007configuration0.2m0.28m4.0mFigure 34 - Side view of LPC 007 configurationWithin the model, the fire is described by a volumetric heat release rate prescribed in aregion measuring 1.8m x 1.3m x 1.1m. The fire was located 0.28m above the floor. A steelobstruction was placed directly below the fire. The heat release rate was prescribed as:HRR = 50.0+0.0082t 2 (kW), for t 300 seconds.Two computational meshes were used for the analysis, one consisting of approximately10,000 cells and another consisting of 21054 cells. The results from these two simulationswere in good agreement with one another. The results presented here are for the meshconsisting of 21054 cells.Two FLOW3D simulations were carried out, in one simulation (FLOW3D_HEAT), thetreatment of the fire was the same as SMARTFIRE, while in the other (FLOW3D_CHEM),a gaseous combustion model developed by FSEG was used. In the FLOW3D_CHEMsimulation, the volumetric heat release rate was replaced by a volumetric mass loss rate ofthe wood crib whose time dependent curve was provided by the LPC report. The heatreleased was determined by oxygen consumption. The heat released from consumingoxygen per unit mass is approximately 13.1 MJ/kg.The FSEG developed six-flux radiation model was used in both cases. The absorptioncoefficient took the following form:a = 0.01, if T < 323K;a = 0.01+0.305/377(T− 323), if 323