基于改进的Mie散射理论计算SiC红外遮光剂对气凝胶辐射传热的影响

Using improved Mie scattering theory to calculate impact of SiC opacifiers on aerogel infrared radiation heat transfer

采用改进的Mie散射理论计算了SiC红外遮光剂对气凝胶辐射传热的影响,计算时考虑了气凝胶基质的吸收特性,并与经典的Mie散射理论结果进行了对比分析,发现遮光剂粒子粒径的大小对计算结果有较大影响。同时,运用改进的Mie散射理论计算了红外遮光剂粒子粒径和添加量对复合绝热材料辐射特性的影响,对粒径为0.877μm、1.9μm、3μm以及4μm,质量分数为15%、25%、35%的SiC红外遮光剂消光系数进行了对比分析,结果与已有实验结果结论一致,而且粒径大小1.9μm质量分数25%时遮光系数比其余选择下的性能优秀。

An improved Mie scattering theory is used to calculate the impact of opacifiers on the aero- gel SiC infrared radiation heat transfer, and the absorption characteristics of aerogel matrix are taken into account during the calculation process. The calculation results are compared with that of the classical Mie scattering theory, and it is found that the opacifiers particle size influences a lot on the calculation results. Meanwhile, the influence of particle size and additive amount of infrared shielding agent on the radiation properties of composite insulation materials is calculated by using improved Mie scat- tering theory, and the extinction coefficient of SiC infrared opacifiers under different particle size of 0.877 μm, 1.9 μm, 3 μm and 4μm and different mass fraction of 15% , 250 , 350 are analyzed. The analysis results show that the optimal shading coefficient is obtained when the particle size is 1.9 μm and the mass fraction is 250, which is consistent with the experimental results.