بهینه سازی عددی 3D پایه مخزن حرارت برای خنک کردن لوازم الکترونیکی

In this paper, the possible optimal thickness of a heat sink base has been explored numerically with different convective heat transfer boundary conditions in a dimensionless three dimensional heat transfer model. From the numerical results, relations among different heat transfer mechanisms (natural or forced, air or liquid), different area ratios of a heat sink to a heating source, and the lowest thermal resistance have been obtained and discussed. Also a simple correlation for these three parameters from data fitting is given for guiding a heat sink design.

It is well known that the performance reliability and life expectancy of electronic equipment are inversely related to the component's temperature. Conventionally, most optimization works on heat sinks assume that the heat is evenly distributed over the entire base area of the heat sink, and therefore, do not account for the additional temperature rise caused by a smaller heat source (the contact area is smaller than the base area) [1] and [2]. Several studies have been carried out to determine this spreading resistance (or called constriction resistance) for a system similar to Fig. 1(a) through numerical or analytical solutions [3], [4] and [5]. However, an optimal result for the base thickness was not obtained in those works for a given boundary condition.In order to cohere with real situations and to pursue the minimum value of thermal resistance of a heat sink with different heat source contact areas, heat transfer boundary conditions and heating flux, in this investigation, a three-dimensional heat transfer models were developed. Through detailed calculations of dimensionless temperature with variations of base thickness and contact area ratios under different heat transfer boundary conditions, the optimal base thickness can be obtained for a certain heat sink configuration. Furthermore, a rigorous experimental test was carried out to verify the reliability of the numerical predictions.

The spreading resistance in a heat sink base with different contact areas and different heat transfer boundary conditions has been investigated numerically with a nondimensionalized 3D heat transfer model and the optimal dimensionless base thickness were obtained. Through the numerical calculations, the detailed temperature distribution in the heat sink base was revealed more clearly than the previous analytical solutions in historic literatures, and the mechanism for which optimal base exists can be understood further.