Abstract: In order to enhance the heat-transfer capability and control the temperature uniformity of the water-cooled heat sink, the relations between the dimensionless thermal resistance and three channel parameters(the number of channels, fin height and fin duty ratio of the heat sink are deduced theoretically in laminar flow range on the condition that the outline dimensions of the heat sink with plate fins and the fluid volume flow are chosen firstly. Then, a parameter optimizing design method with application to arbitrary heat sink dimensions which is of good directive significance in engineering is presented according to these variation relations. The results of simulation and experiment prove the effectiveness of the method and show that, the heat-sink with small channel sizes can reach higher heat-transfer efficiency and is more effective to cool the component with big heat-flux density, the heat-transfer efficiency decreases with the increase of volume flow, so the volume flow should be selected reasonably with comprehensive consideration of the control requirements of the heat-sink flow resistance and fluid mean temperature rise.

Key words: Computational fluid dynamics(CFD), Optimization design, Power electronics, Water-cooled heat sink