doi:10.3850/978-981-08-7724-8_04-03

ABSTRACT

A mixture fraction based discrete reaction model (DRM) for sooting flames is extended through the use of a presumed probability density function (PDF) for the mixture fraction and implemented into FireFOAM, which is a LES solver based on the open source CFD code OpenFOAM. The filtered equations are closed by a sub-grid scale (SGS) model which solves a transport equation for SGS kinetic energy. While a finite volume based model has already been implemented into FireFOAM and is undergoing through separate testing, radiation in the present study is treated with the P-1 model which is the simplest case of the more general P-N method. Due consideration is given to the different absorption and emission coefficients of gases and soot particles. The extended model is tested with the experimental data for a one metre diameter methane fire. Overall, the predictions are in reasonably good agreement with the experimental data. Although some discrepancies are found and discussed, the study has demonstrated good potential of the extended DRM for predicting pool fires within the LES framework.

Keywords: Discrete reaction, Soot, Large eddy simulation, Pool fire.

© 2011 CPD Unit, University of Leeds