漫反射下两层散射性介质内的瞬态耦合换热

采用光线踪迹 /节点分析法研究了在漫反射、表面不透明、分界面半透明的两层平板状吸收、各向同性散射性非灰介质内的辐射与导热瞬态耦合换热。两层介质具有不同的辐射特性 ,折射率均大于等于 1。在考虑表面多次反射和介质多次散射的情况下 ,推导了复合层辐射传递系数 ,由辐射传递系数计算辐射热源项。在对流、辐射换热边界条件下 ,采用控制容积法求解瞬态能量方程 ,获得了复合层内的稳态、瞬态温度场和热流密度 ,与 Galerkin法的计算结果比较 ,表明该文的计算方法正确 ,精度高

Transient coupled conduction and radiation heat transfer in a two-layer scattering media with diffuse reflective boundary

Transient coupled radiation and conduction in a two layer isotropic scattering semitransparent non|gray medium with thin opaque coatings was studied by ray tracing/nodal analysis method. Both boundary surfaces were opaque and diffuse, and the interface between the two layers was semitransparent. The two layers had different thermophysical characteristics and the refractive indices were greater than 1. The radiative transfer coefficients of the composite were deduced for diffuse reflection, with multiple reflections at the surface and multiple scattering in the media. The radiative heat source term was calculated from the radiative transfer factors. The transient energy equation was solved by the control|volume method. The steady|state and transient temperature distributions and heat flux densities in the composite were obtained for the general boundary conditions of external radiation and convection. A comparison of the present results with previous results obtained with the Galerkin method shows that the equations are correct and the results are more accurate.