Impingement heat transfer of a plate fin heat sink with fillet profile

The fluid flow and thermal characteristics of an air-impinged plate fin heat sink was investigated numerically to understand the effect of fillet profiles at the bottom of the plate fin. The numerical model is validated against existing literature. The results of pressure drop and mean Nusselt number were obtained for cases with and without fillet profiles for variable channel widths and inlet widths. It is found that fillet profile enhances the overall thermal performance of a plate fin heat sink, and the U-shaped channel profile is capable of achieving thermal enhancement as high as approximately 13%. The fillet profiles altered the flow pattern such that the flow is smoothened near the bottom of the plate fin, reducing the negative impact induced by the rebounding flow. Furthermore, the addition of fillet profiles at the bottom of the plate fin reduces the constriction resistance and contributes to the overall thermal enhancement.