Experimental investigation on flow and heat transfer characteristics of the drop-pressure microchannel heat sink with gradient distribution pin fin arrays and narrow slots

Abstract

Aiming to improve the problem of excessive pressure drop in microchannel heat sink (MCHS), a drop-pressure microchannel heat sink with gradient distribution pin fin arrays and narrow slots (DP-MCHS-PS) was proposed and its hydraulic properties were experimentally studied. Due to the addition of narrow slots, the pressure drop of the DP-MCHS-PS tends to increase less with the gradual increase of the volume flowrate. The pressure drop of the DP-MCHS-PS decreases by 56.3 % and 52.7 % when compared with the conventional gradient distribution and uniform distribution; Meanwhile, the temperature distribution within the microchannel was studied and found that although the heat transfer performance of the DP-MCHS-PS was decreased, the uniformity of surface temperature distribution was still retained. The study also comprehensively evaluated the heat transfer performance of the DP-MCHS-PS in terms of the effect of the average absolute temperature difference, heat transfer coefficient, Nusselt number and pump power on the thermal resistance, also investigated the effect on surface temperature in the presence of hot spots on the chip surface.