Modeling turbulence-radiation interaction in confined diffusion flames

摘要

Modern accuracy requirements for simulations of confined turbulent combustion systems motivated numerous investigations of the complex problem of radiative heat transfer in fluctuating flow fields. Stochastic methods have been used to analyse the major features of this physical phenomenon and have illustratedits importance in many engineering applications. The present paper will discuss the feasibility of an approach based on the thin eddy assumption for middle size combustion chambers. Emphasis is given to the problem of simultaneous fluctuations of heat release ratio and mixture fraction which is modeled with a two dimensional probability density function in order to describe the specific behavior of diffusion flames in confined environments. This model is used to estimate averages toward the numerical procedure; in particular to compute the average radiative emission with correlated fluctuations of radiative properties, water vapor and carbon dioxide concentrations, and blackbody intensity.