Transient coupled heat transfer in a multi-layer composite with opaque specular surfaces and semitransparent specular interfaces

Abstract

In this paper, one-dimensional transient coupled radiative and conductive heat transfer in a multi-layer absorbing and isotropic scattering composite is investigated. The composite is considered to be of opaque specular boundaries and semitransparent specular interfaces. In combination with ray tracing method, spectral band model and the Hottel and Sarofim's zonal method, the radiative transfer coefficients (RTCs) of the multi-layer composite are deduced. The RTCs are used to calculate the radiative heat source term in the transient energy control equation, which is solved by the fully implicit discrete control-volume method. The effects of refractive index and vacuum space on transient coupled heat transfer are analyzed. Except for refractive index, all the other parameters of each layer have been kept the same, and the total thickness also has been kept unchanged, then along the thickness of the composite when the decrement or the increment of refractive index decreases as layer number increases, the temperature profile becomes smoother and the steady heat flux increases.