doi:10.3850/978-981-08-7724-8_12-05

ABSTRACT

A sub-grid model for soot-radiation in fires is proposed and implemented in a turbulent CFD fire model. The mechanisms of soot formation, oxidation and radiation are modeled by imposing a spatially uniform strain rate that compresses a two-dimensional slab of fuel with oxidant flowing in onto both sides of the slab. Conservation equations for mixture fraction, total enthalpy, and soot are solved using mathematical transformations. An LES validation study is performed for turbulent slot burner flames with various fuel types and heat release rates. The model, based on the fuel smoke point, currently predicts the radiant fractions for hydrocarbon fuels burning in air. A second LES study is conducted to compute radiant heat fluxes on inert parallel panels from a 60 kW turbulent flame. Computed results are compared against experimental data.

Keywords: Soot, Smoke point, Radiation, Diffusion flame, Turbulent flame.

© 2011 CPD Unit, University of Leeds