Numerical study of thermal enhancement in a micro-heat sink with ribbed pin-fin arrays

Abstract

Targeted at improving comprehensive hydro-thermal performance of microfluidic cooling, a new type of ribbed pin-fin arrays heat sink is proposed. To reveal the mechanism of heat transfer enhancement in inline ribbed pin-fin arrays heat sink (RPHS), the comparisons among smooth microchannel heat sink (MCHS), inline cylinder pin-fin arrays heat sink (CPHS) and RPHS with coolant of deionized water are studied by numerical simulation with laminar flow (360 ≤ Re ≤ 780). Due to the flow disturbance and destroying of boundary layer, RPHS shows the best performance in heat dissipation and uniformity of temperature distribution among the three configurations. The average Nusselt number of RPHS reaches up to 23.1 which is almost twice of CPHS and three times of MCHS when Re number is 780. Meanwhile, the non-dimensional parameter He is proposed to evaluate the temperature distribution of bottom baseplate. RPHS has the lowest total thermal resistance under the same pumping power. Moreover, the entropy generation of RPHS is lower than MCHS and CPHS under the same operating condition. Conclusively, RPHS exerts the best comprehensive hydro-thermal performance.