A fully-coupled simulation of vortical structures in a large-scale buoyant pool fire

A numerical study simulating the temporal vortical structures of a large-scale buoyant pool fire has been carried out using a fully-coupled Large Eddy Simulation (LES) model which incorporates all essential subgrid scale (SGS) turbulence, combustion, radiation and soot chemistry considerations. Based on the strained laminar flamelet approach, a scalar dissipation conditioned SGS combustion model is introduced to distinguish the highly non-equilibrating burn and extinguishment of flamelets commonly found in pool fires. Numerical results from the present model are validated and compared against a one-meter diameter methane pool fire experimental data and predictions from other LES field models. The predicted time-averaged velocity and temperature profiles have been found to be in good agreement with the experimental data and those numerical results. Qualitative comparisons of instantaneous velocity field against experimental data have revealed that the dynamic phenomena of large-scale vortical structures and its associated puffing behaviour of pool fire are well captured. Quantitative comparisons of velocity time history and pulsation frequency also show close agreement against experimentally evaluated quantities.