A model for soot radiation in buoyant diffusion flames

被引：50

作者：

Chatterjee, Prateep ^{[1
]}

de Ris, John L. ^{[1
]}

Wang, Yi ^{[1
]}

Dorofeev, Sergey B. ^{[1
]}

机构：

[1] FM Global, Div Res, Norwood, MA 02062 USA

来源：

PROCEEDINGS OF THE COMBUSTION INSTITUTE | 2011年 / 33卷

关键词：

Soot; Smoke point; Radiation; Diffusion flame; Turbulent flame;

D O I：

10.1016/j.proci.2010.06.112

中图分类号：

O414.1 [热力学];

学科分类号：

摘要：

A subgrid soot-radiation model in fires is proposed and implemented in a turbulent CFD fire model. Experiments have established that soot formation rates in fires are governed by the Kolmogorov straining rate and by the chemical time for soot formation, which is inversely proportional to the fuel's smoke point. The mechanisms of soot formation, oxidation and radiation are modeled by imposing a spatially uniform transient strain rate that compresses a two-dimensional slab of fuel with oxidant flowing towards both sides of the slab. Conservation equations for mixture fraction, total enthalpy, and soot for a transient straining rate are solved using mathematical transformations. Effects of radiant heat loss and variable specific heats are treated and the rates of soot formation and oxidation are expressed as functions of temperature and mixture fraction. An LES validation study is performed for optically thin buoyant turbulent 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. It is also shown that with increasing heat release rate, overall radiant fraction from the flames do not increase for a given fuel type. (C) 2010 The Combustion Institute. Published by Elsevier Inc. All rights reserved.

引用

页码：2665 / 2671

页数：7

共 15 条

[1] Effect of radiative heat loss on diffusion flames in quiescent microgravity atmosphere [J].