APPLYING THE BOUNDARY ELEMENT TECHNIQUE TO THE SOLUTION OF HEAT RADIATION PROBLEMS IN CAVITIES FILLED BY A NONGRAY EMITTING-ABSORBING MEDIUM

Abstract

Because heat radiation is governed by integral equations, the numerical procedures and codes of the boundary element method (BEM) can be readily adapted to solve heat radiation problems. Two alternative representations of the integral equations of radiative heat transfer are derived, the first containing a volume integral and the other using only surface integrals. It is demonstrated that the known Hottel's zoning technique is a specific case of the weighted residual solution of the first representation. The boundary-only formulation is discretized by employing standard BEM, i.e., collocation and locally based interpolating functions defining both the geometry and the variation of the unknown functions. Numerical examples are included