Analysis of Fluid Flow and Heat Transfer in Corrugated Porous Fin Heat Sinks

Abstract

This study reports on a mathematical model for predicting the fluid and heat flow characteristics of a Z-shaped corrugated foam heat sink. Experiments were carried out to validate local as well as overall pressure drop predictions. The mathematical model was further validated against corrugated carbon foam experimental measurements from the literature. A general flow parameter emerges from the formulation that is descriptive of flow uniformity. Based on a scaling analysis, it was found that a relatively low permeability foam, compared to the square of the conduit hydraulic diameter, is more effective than high permeability foam because of its ability to achieve uniform flow distribution. An illustrative study is carried that estimates the optimum number of porous fins that can be packaged within a given volume under fixed pressure drop constraint. Further, this study elaborates on the importance of achieving uniform flow distribution across the porous fins. The ideal condition of uniform flow was found to be useful in increasing the rate of heat transfer when compared with the actual condition of non-uniform flow for the range of parameters explored in this work. Finally, the impact of the flow non-uniformity parameter on the overall Nusselt number is illustrated.