散射对高温气体-碳黑颗粒混合物辐射传输的影响

基于全光谱k分布(Full spectrum k distribution,FSK)模型、MIE理论和有限体积法(Finite volume method,FVM),构建了均温、均质辐射参与性气体-碳黑颗粒混合物介质热辐射传输模型,并分析了碳黑不同尺寸、不同体积浓度以及介质不同路径长度和不同温度条件下,因忽略碳黑颗粒散射所导致的介质热辐射传输特性(如辐射热流、辐射源项)的计算误差。研究结果表明:体积分数不变,增大粒径,计算误差呈现出先增大后减小的趋势;数密度不变,增大粒径,或者粒径不变,增大体积分数,均将使得计算误差相应增大;粒径、体积分数不变,增大路径长度,或者升高介质温度,均将增大计算误差。通常对于含有大颗粒、高碳黑浓度的辐射参与性气体-碳黑颗粒混合物介质,碳黑颗粒散射不能忽略。

Influence of Scattering Effect of Soot on Radiative Transfer in High Temperature Gas-Soot Mixtures

The full spectrum k distribution (FSK) model, MIE theory and finite volume method (FVM) are applied to construct the radiation transfer model in the isothermal and homogeneous high temperature gas-soot mixtures. Under different soot sizes, different soot volume fractions, different path lengths and different temperatures, the calculated errors of radiative heat transfer properties (such as the radiative heat flux and radiative source term) due to neglecting the soot scattering effect are studied. The research results reveal that when increasing the soot size with the soot volume fraction unchanged, the calculated errors will increase first and then decrease. When increasing the soot size with the soot particle number density unchanged or increasing the volume fraction with the soot size unchanged, the calculated errors will increase monotonously. When the soot size and the volume fraction unchanged, increasing the radiative heat transfer path length or increasing the medium temperature, the calculated errors will also increase monotonously. Therefore, for high temperature gas-soot mixtures with large particles or large soot volume fraction, the soot scattering should not be ignored.