基于离散坐标法的辐射模型研究

The Evaluation of WSGGM Based on the Discrete Ordinates Method

在分解温度以下的辐射气体,其吸收系数随着波长有剧烈的变化,因此在计算中考虑气体的非灰辐射特性是非常必要的,加权灰气体和模型是一种相对比较简单的考虑气体的非灰特性的模型。本文采用离散坐标法和加权灰气体和模型结合计算了三维固定空间内气体辐射,并以统计窄谱带模型的结果为基准,检验了几种加权灰气体和模型的精度。同时研究了不同离散坐标方式对WSGGM模型计算精确性和计算效率的影响。

Molecular gases below the dissociation temperature absorb and emit over a multitude of very narrow spectral lines, which may overlap and form vibration-rotation bands. So it is important to consider the non-grey characteristic for the computation of radiative heat transfer of the participating gas media. The weighted-sum-of-gray-gases model(WSGGM) is a relatively simple model to deal with the non-grey characteristic of the gas media. Three-dimensional non-grey gases radiation analyses were conducted using WSGGM and the discrete ordinates method. Three kinds of WSGGMs were tested and evaluated using results of the model case. The influences of different kinds of approximated discrete ordinates sets on the model accuracy and computational efficiency of WSGGM are also studied.