Etude Numérique des Transferts de Chaleur onjugués Lors du Refroidissement des Sources de Chaleur

Abstract

We treat the problem related to heat transfer by natural convection through a three-dimensional numerical simulation study of two identical blocks heated and separated by a distance d, simulating the air cooling (assumed incompressible Newtonian) electronic components in a cuboid cavity . Each block is maintained at a temperature Tc (hot), which varies depending on the Rayleigh number, in the center of the bottom wall of the enclosure, the remainder of the surface is assumed adiabatic, while the other walls are maintained at a constant temperature Tf (cold). The presentation of the physical model is translated into mathematical equations in the form of partial derivatives (E.D.P), which regulates the transport of energy by molecular motion in the cavity. Based on certain assumptions for which these equations are valid, these mathematical expressions mainly include fundamental laws: conservation of mass, momentum, and energy. According to the complex nature of these equations (nonlinear and coupling velocity-pressure), we are facing the numerical resolution. In this context, a computer code was developed at the base of Fortran language, and validated by the work found in the literature. In the first part, our effort is focused on the laminar flow trying to clear the influence of the effects of the Rayleigh number, spacing, and aspect ratio of the length and the width components of the physical behavior of fluid, such as the flow and heat fields. In the second part, the transitional arrangements made in our study through early detection of hydrodynamic and thermal instabilities, however, we discuss the spacing influence, reports form the length and the width components of the flow bifurcation. Finally, stability diagrams were established according to these parameters.