Flow and thermal radiation characteristics of a turbulent flame by large eddy simulation

摘要

Liquid fuel pool fire flame is a common combustion problem for liquid oil in many practical applications. Thermal radiation has considerable effect on its combustion process and fire spread. Based on the large eddy simulation method of the fireFOAM framework, the flame properties and thermal radiation characteristics of a 1m diameter methanol pool fire are investigated. The flame structure features frequent buoyance-driven upward movement and air entrainment from surrounding environment due to turbulent mixing and combustion. The radiative heat feedback shows strong temporal and spatial variations, which is caused by the fluctuating behaviors of the temperature and species fields. The radiation transfer models have significant discrepancies in predicting the radiative heat feedback for all the surfaces with the weighted-sum-of-gray gases model producing better results. Ray effects of the solvers lead to unphysical non-uniform distributions of radiative heat flux on the bottom and side walls.