Transient thermal analysis of semitransparent composite layer with an opaque boundary

Transient coupled radiative and conductive heat transfer in a two-layer, ab sorbing, emitting, and isotropically scattering non-gray slab is investigat ed by the ray tracing method in combination with Hottel's zonal method. One outer boundary is opaque, and another is semitransparent. The radiative en ergy transfer process in a semitransparent composite is divided into two su b-processes, one of which considers scattering, the other does not. The rad iative transfer coefficients of the composite are deduced under specular an d diffuse reflection and combined specular and diffuse reflection, respecti vely. The radiative heat source term is calculated by the radiative transfe r coefficients. Temperature and heat flux are obtained by using the full im plicit control-volume method in combination with the spectral band model. T he method presented here needs only to disperse the space position, instead of the solid angle. A comparison with previous results shows that the resu lts are more accurate. (C) 2001 Elsevier Science Ltd. All rights reserved.