Characterization of compact heat sink models in natural convection

Abstract

The modeling of heat sinks was carried out by using the electronics cooling software for natural convection scenarios in vertical configurations. Simulations were carried out using the electronics cooling CFD software on both actual and compact heat sink models to evaluate the thermal efficiency of the heat sink. The effective thermal conductivity of the compact heat sink was calculated using Nusselt number correlation for free convection on a vertical plate. Due to the complex nature of the Nusselt number correlation for free convection on a vertical plate, an iterative solution was used in order to solve for the effective conductivity of the compact heat sink. The use of compact heat sink models helps to reduce the cost of computing time and resources. The compact modeling technique was first applied to both extruded and pin fin heat sinks to validate the methodology in laminar natural convection scenarios. After validating the methodology in laminar natural convection scenarios, it was applied to a system level model consisting of a set of pin fin heat sinks placed on a row of components. It was found that the compact heat sink technique results in significant savings in mesh size and computing time and also gives good accuracy when compared with the results from the detailed heat sink models.