NUMERICAL ANALYSIS OF NATURAL CONVECTIVE AND RADIATIVE HEAT TRANSFER IN AN ARBITRARILY SHAPED ENCLOSURE

The flow and thermal characteristics of the interactions of natural convection and radiation in an enclosure containing circular ducts are analyzed numerically. For calculation of flow fields, the SIMPLE algorithm originally developed in Cartesian coordinates is extended and modified to apply to the curvilinear coordinates system. The radiation part of the problem for an arbitrarily shaped domain is solved by using the finite volume method (FVM). Cartesian velocity components are used as the dependent variables in momentum equations, and a nonstaggered grid system is employed. The flow and thermal fields for an irregular geometry are investigated for the variation of such parameters as scattering albedo, optical thickness, and Planck number. The test problem is compared with both the exact solutions and the discrete ordinates method solution. The results show that the FVM is an effective method to predict radiative heat transfer processes in irregular geometries and that the change of optical thickness has more effect than that of scattering albedo on flow and thermal fields.