Abstract:

The thermal resistances of micro/mini circular shaped pin-fin heat sinks are from the heat conduction through the sink bottom layer and the pin fins, the heat convection of cooling liquid between the sink layer and the pin fins, and the enthalpy change of the cooling liquid.The heat transfer characteristics through the bank of circular shaped micro/mini pin-fin heat sinks are investigated experimentally with deionized water as cooling fluid and by heating at constant heat flux over Reynolds numbers ranging from 100 to 1000, with the heating power in the range of 50—300 W.It is found that the convective heat transfer coefficient increases with the volume flow rate of cooling fluid and the Nusselt number increases with the increase of the Reynolds number and the heating power.As the volume flow rate of fluid increases, the total thermal resistance of the heat sinks decreases exponentially and gradually reaches a constant value.The experimental results show that the height of micro/mini pin fins of the heat sinks has little effect on the convective heat transfer and there is no difference in the total thermal resistance and different heights of micro/mini pin fins as the volume flow rate changes.The experimental results are compared with some relations in literature, and the Zukauskas relation is appropriate to predict the Nusselt number.