Soot in combustion simulations

Soot is the dominant source of radiative heat transfer from most practical flames. A review is presented of historical, empirical modelling approaches for estimating heat flux from fires and flames. These historical methods have drawn on empiricism to address the role of soot while seeking methods for including the multi-scale effects of soot formation and flame structure. Both soot concentration and flame temperature have been seen to be local phenomena with dimensions on the order of the diffusion and chemical (Batchelor) scales of the flame. The correlation between the local soot volume fraction and the local temperature field is needed for determining the radiant heat flux from the flame. By using high performance computers (hundreds to thousands of processors) Large Eddy Simulations (LES) can resolve structures on the scale of the pool diameter in pool Hires. Thus, air engulfment and visible flame structure are resolved. Manifolds for the gas-phase chemistry, soot formation, particle growth, soot diffusive/ thermophoretic transport are used to bridge the Batchelor and resolved (LES) scales.