PhD Thesis - staffweb - University of Greenwich

APPENDIX 1 : SMARTFIRE VERIFICATION AND VALIDATION REPORTBi-directional velocity probes and bare-wire thermocouples were placed within the roomopening on a two-dimensional grid of 28 to 144 depending on the size of the opening tomeasure velocities and temperatures within the centre of the door jamb. The measuredvelocities may be subject to up to 10 percent error. In addition, a stack of aspiratedthermocouples was placed in the front corner of the room to measure the gas temperatureprofile.In the test selected here, the door measured 0.74m wide and 1.83m high and the fire, whichwas centrally located on the floor (position A in Figure 26), was represented by a gas burnermeasuring 0.3m in diameter. The burner power was 62.9 kW.In the CFD case it is assumed that the fire is a volumetric heat source measuring 0.3m x0.3m x 0.3m with a heat release rate of 62.9 kW.3.1.1 ResultsThe SMARTFIRE results are compared with the experimental data and predictions madeusing FLOW3D (see Figure 27, Figure 28 and Figure 29). Both SMARTFIRE andFLOW3D used 200 one second time steps. The mesh budget consisted of 9918 (29×18×19)cells. In these calculations it was assumed that the walls were composed of common bricks.The six-flux radiation model was used with a temperature dependent absorption coefficient.2.5height (m)Corner Temp21.5testflow3dsmartfire10.5temp (K)0300 320 340 360 380 400 420Figure 27 –Vertical Corner Stack temperatures at 0.305 from the front wall and side.Both FLOW3D and SMARTFIRE give reasonable agreement with the experimental resultfor the vertical thermocouple stack in the corner of the room ( Figure 27). NeitherSMARTFIRE or FLOW3D capture the hot stratification layer very well but this can at leastin part be attributed to the relative coarseness of the mesh.Appendix 11.1 Page 141-24 24