Application of a subgrid soot-radiation model in the numerical simulation of a heptane pool fire

Predictions of temperature, soot volume fraction and incident radiant flux are presented from large-eddy simulations of a medium-scale heptane pool fire. A subgrid soot-radiation model, which is based on the laminar smoke point concept, is applied to provide local emission from the turbulent flame-sheet. A local absorption coefficient is estimated using the local emission, mesh resolved temperature and its modeled subgrid variance. Absorption-emission calculations are conducted with the solution of the radiative transport equation (RTE). The results obtained from the fire simulations including velocity, temperature, volumetric emission and soot concentration distributions are compared with general observations from the experiment. Radial profiles of temperature and soot volume fraction are also compared with experimental data at several heights above the burner. Predicted temperature profiles are found to generally agree with the experimental data. Soot volume fraction predictions show similar trends as experimental measurements with positive and negative deviations. Incident radiation at an axial location away from the fire shows good agreement between the model and the experiment.