BRDF表面对一维梯度折射率介质内辐射传热影响

The Effect of BRDF Surface on Radiative Heat Transfer Within a One-Dimensional Graded Index Medium

辐射计算中的漫反射或镜反射假设并不足以完整地描述实际表面的特性.本文首次将BRDF、表面引入辐射传热分析。使用Minnaert模型模拟BRDF表面,通过遗传算法得到模型参数.用DRESOR法和逆蒙特卡洛法求解了含BRDF表面的-维梯度折射率介质中的辐射传热问题。计算结果显示了DRESOR法和逆蒙特卡洛法的准确性。虽然BRDF表面和相应的漫反射表面对应的温度偏差仅为±1.5%,但辐射热流偏差高达±10.5%,这足以引起很大的分析误差,实际辐射热分析中应引起重视。

The traditional diffuse or specular surface assumption is insufficient to fully characterize a real surface.The BRDF surface is introduced into the radiative heat transfer problem for the first time.A Minnaert model for the BRDF surface is applied and the genetic algorithm is used to obtain the parameters of the proposed model.The DRESOR method and the RMC method are extended to solve the radiative heat transfer within a 1-D absorbing,emitting and scattering graded index medium with BRDF surfaces.The results obtained by the DRESOR method and the RMC method indicate the accuracy of the calculation.Compared with the corresponding diffuse surface,though the relative temperature difference of the BRDF surface is ±1.5%,the radiative flux increases significantly by±10.5%.This is enough to cause large error,which should be pay attention to in the radiative heat transfer problem.