Measurement of thermal and hydraulic performance of a plate-fin heat sink with a shield

Abstract

To assess the performance of plate-fin heat sinks with the introduction of a shield in a cross flow, we analyzed the surface temperature of the base of the heat sink with an infrared thermograph to determine the effects of shield, fin height, fin width and Reynolds number on the thermal resistance. The introduction of a shield decreases the bypass flow effect and forces more coolant fluid to enter the channel from fin to enhance the heat transfer. Increasing the Reynolds number decreases the thermal resistance of the heat sink, but that decrease tends to diminish with increasing Reynolds number; the enhancement of heat transfer by the heat sink is limited when the Reynolds number attains a particular value. For a given fin width, the thermal performance of the heat sink with the highest fins is superior. For a given fin height, the optimal fin width in terms of thermal performance increases with increasing Reynolds number. As the fins become wider, the flow passages in the heat sink constrict the entrance of coolant air; as the fins become narrower, the area of heat transfer of the heat sink decreases. Both conditions decrease the heat transfer of the heat sink.