Numerical calculations for combined conduction and radiation transient heat transfer in a semitransparent medium

A numerical computer code was developed for calculating the combined conduc tion and radiation transient heat transfer in cylindrical, semitransparent materials that have temperature-dependent thermal properties. The radiative component is combined with the equation of conduction heat transfer by add ing it as a heat source. The finite element method (FEM) was used for calcu lating the radiative component and for solving the temperature field in the medium. Very good agreement was observed between results obtained by using our code and those that exist in the literature for several steady-state c ases. The advantage of the code is due to the fact that it incorporates tem perature-dependent properties; thus it leads to more realistic and accurate results. The code was applied to calculate the cooling path of a large cyl indrical sapphire boule while using varying, transient, temperature-depende nt, combined heat transfer coefficients.