Transient coupled heat transfer in three-layer composite with opaque specular surfaces

A ray tracing/node analyzing method is applied to investigate one-dimensional transient coupled radiative and conductive heat transfer in a three-layer absorbing and isotropically scattering composite with opaque specular surfaces and semitransparent specular interfaces. The reflectivities of the semitransparent interfaces are angularly dependent and determined by Fresnel's reflective law and Shell's refractive law. The radiative transfer coefficients for calculating the radiative heat source term are deduced by the ray tracing method in combination with the zonal method. The transient energy equation is solved by the fully implicit control-volume method in combination with the spectral band model. The effects of surface emissivity, scattering albedo, refractive index and extinction coefficient on transient coupled heat transfer are investigated in detail under radiative and convective boundary conditions.