Mie散射偏振特性对平板介质内辐射换热的影响

EFFECT OF MIE SCATTERING POLARIZATION ON THERMAL RADIATIVE TRANSFER IN A SLAB

偏振是电磁辐射的重要特性之一。考虑偏振效应的辐射传输的分析和计算需要基于以Stokes参量为传输变量的矢量辐射传输方程。由于考虑偏振效应时辐射换热计算要复杂得多，传统的辐射换热计算过程中一般忽略偏振效应。而完全忽略偏振效应对辐射换热的分析可能会引起较大的误差。本文通过数值求解矢量辐射传递方程，以平行光照射一维散射平板为例，研究由Mie散射相矩阵引起的偏振效应对辐射换热的影响。研究表明，入射光的偏振态和散射相矩阵的偏振效应是耦合在一起对辐射换热的分析产生影响的。当它们具有强的耦合作用时，即偏振态显著影响散射后的能量分配，将会引起基于标量辐射传输的辐射热流预测结果出现较大偏差。

Polarization is an important characteristic of electromagnetic radiation. Analysis of radiative transfer with considering the effect of polarization is based on the vector radiative transfer equation, in which the vector of Stokes parameters is taken as governing variable. Because it is too complicate for considering polarization effect in thermal radiation analysis, the effect of polarization is often neglected in common thermal radiation analysis. It may cause large error when the effect of polarization is totally omitted. The effect of polarization on the thermal radiative transfer in an infinite slab is analyzed through numerically solving the vector radiative transfer equation. It is observed that the polarization state of the incident beam and the polarization characteristic of the phase matrix is coupled together to take effect in influencing the predicted radiative heat flux. The effect of polarization is noticeable only when the characteristic of phase matrix is strongly coupled with polarization state of the incident beam, namely, the scattered intensity distribution is remarkably altered for different polarization state of incident beam. In such circumstances it will cause large deviation of scalar radiative transfer analysis.