Application of the boundary element method in radiation

Two applications of the boundary element technique to radiative analysis are discussed: radiation in participating media and the presence of concave, self irradiating cavities in heat conducting bodies. When compared with classic Hottel's zoning approach, BEM leads to shorter computing times. This is achieved because the most time consuming procedure of Hottel's approach, volume integration, can be avoided. Additionally, instead of multiple integrals only a single integration ought to be performed. The paper presents a general, self adaptive quadrature capable of evaluating integrals over the elements located close to the observation point. The paper shows also an original technique of coupling heat radiation and conduction. Both problems are solved by using BEM. Static condenstation of linear unknowns before entering the iterative loop, makes this approach very efficient. Numerical examples are included.