Abstract
We consider the integral equation arising as a result of heat
radiation exchange in both convex and nonconvex enclosures of
diffuse grey surfaces. For nonconvex geometries, the visibility
function must be taken into consideration. Therefore, a
geometrical algorithm has been developed to provide an efficient
detection of the shadow zones. For the numerical realization of
the Fredholm integral equation, a boundary element method based on
Galerkin-Bubnov discretization scheme is implemented.
Consequently, multigrid iteration methods, which are closely
related to two-grid methods, are used to solve the system of
linear equations. To demonstrate the high efficiency of these
iterations, we construct some numerical experiments for different
enclosure geometries.