Natural Convection Air cooling of Electronic Components in Partially top vented Enclosures

Abstract

The study of natural convection from a heat source located at the bottom of partially top vented enclosure is presented. Air cooling for electronic components

situated at the bottom of a top vented enclosure is studied theoretically. The flow was assumed to be laminar, steady and of constant physical properties. The process was described by the continuity, momentum and energy partial differential equations, which were expressed in Cartesian coordinates system. Due to the nature of the studied problem and with proper transformation, at the dependent and independent variables, these governing equations were expressed by a set of dimensionless partial differential equations. This set of differential equations is transformed to set of difference equations by the implantation of a finite difference technique. Accordingly, the solutions for this problem were obtained by the application of the well-known Gauss Siedel iteration method. A computer program, by using FORTRAN-90 language, was developed to solve the present proposed mathematical model. According to this solution; the values of Nusselt number, for different values of Rayleigh number are obtained. Comparisons between the present obtained results and those results obtained in previous theoretical results were performed for parametric variations of the vent opening size and shape. Also a correlation for Nusselt number as a function of Rayleigh number and equivalent diameter of the vent is proposed.