Modelling of conduction-radiation in a porous medium with blocked-off region approach

A new methodology to solve a heat transfer problem in a complex porous structure has been proposed in this work. The 3D numerical model considers combined conductive-radiative heat transfer with the finite volume method integrated with a blocked-off region approach. The model is capable of considering grey, diffuse behaviour of the surfaces of the solid. The work demonstrates the simplicity of this approach for solving problems with porous structure by eliminating the complexity of grid generation generally needed for any conventional methods. The representative porous structures considered for this analysis are cubic cell and honeycomb structures. The effective thermal conductivity is determined for different temperature, emissivity and thermal conductivity of the solid and absorption coefficient of the fluid. Various problems are also solved in order to validate the formulation and the subsequent implementation with the results from FLUENT 6.3 as well as literature. A good agreement of the results has been observed and reported in the paper.