PhD Thesis - staffweb - University of Greenwich

APPENDIX 1 : SMARTFIRE VERIFICATION AND VALIDATION REPORT2.6 Turbulent buoyancy flow in a cavity.This test case examines the turbulence model, turbulent heat transfer and buoyancy model.The test case is a standard test case which has been used by a number of other investigators[3] and forms part of the PHOENICS test library. The turbulence model used bySMARTFIRE is based on the model of Launder and Spalding [4].The geometry used for this case is depicted in Figure 17 below.Fluid propertiesconductivity is 2.852158e-02 (W/mK)density is 1.071 (kg/m 3 )specific heat is 1.008e+03 (J/kgK)viscosity is 2.0383e-05 (kg/ms)thermal expansion is 3.029385e-03 (1/K).Boundary conditionshot wall (t h ): constant temperature (353.0 K)cold wall(t c ): constant 307.2 (K).The other walls are adiabatic.The cell budget is 14400(120×120) with non-uniformly distributed mesh.The Boussinesq approximation is used to model the buoyancy. As the flow lies in the lowMach number region (i.e. subsonic) and there is a small temperature difference between thewalls, then the Boussinesq approximation is extremely good and therefore the use of a fullyturbulent treatment is unnecessary.Appendix 11.1 Page 141-17 17