Transient radiation and conduction heat transfer inside a plane-parallel participating gray medium with boundaries having different reflecting characteristics

A hybrid ray-tracing method is developed for the solution to the radiative transfer in a plane-parallel participating medium having one specular surface and another diffuse surface. By this method, radiative transfer coefficients (RTCs) for specular-diffuse (S-D) surfaces are deduced. The medium surfaces are considered to be semitransparent. The effects of convection-radiation parameter, conduction-radiation parameter and refractive index on transient coupled heat transfer are investigated. Results show that the temperature curves of the medium having S-D surfaces is higher than those of the medium having S-S surfaces (two specular surfaces); the total heat flux at steady state for the S-D surfaces is lower than that for the S-S surfaces.