Investigation of turbulence models for CFD simulations of gas and liquid pool fires

The effect of turbulence models on CFD predictions of gas and liquid pool fires is investigated. A buoyancy-modified four-equation (4EQ) model and two modified versions of the standard two-equation(2EQ) k-ε model are employed for simulating three pool fire scenarios. The 4EQ model includes all the important source terms in the turbulent heat flux expressions and emphasizes the anisotropy of turbulence due to buoyancy effects by adding an algebraic term to the eddy-viscosity expression of Reynolds stresses. Predicted results show that the 4EQ model predicts far larger values of buoyancy production of turbulent kinetic energy than the 2EQ models, and consequently achieves better agreement with experimental temperature and velocity data