Abstract
The cooling of electronic components on a circuit board by cross-flow mixed convection was analyzed in the present study. In this class of flow, the orthogonal free and forced convection result in a three-dimensional boundary layer flow. It was attempted to identify and analyze the significance of the factors that influence the local heat transfer rate and the surface temperatures of these components. A simple two-dimensional model of a thin plate with stripwise heat sources on it was considered first and it was found that having an external cross-flow results in lower surface temperatures than having an aiding flow. Next, a more practical three-dimensional model of a conducting board of finite thickness with four heat sources mounted on the surface was analyzed. Heat transfer from both sides of the board was taken into account. The conservation equations for mass, momentum, and energy were solved. The important factors that influenced the heat transfer mechanism were the distance of the heat sources from the natural as well as the forced convective leading edges, spacing between the sources, the Richardson number, Reynolds number, board thickness, and the properties of the board material.
