Effects of geometric parameters of circular pin-fins on fluid flow and heat transfer in an interrupted microchannel heat sink

A novel interrupted microchannel with double circular pin-fins in each microchamber (IMCDCP) is designed to combine the advantages of microchamber and circular pin-fin in heat transfer enhancement. The effects of the diameters (d1, d2), spacing (s) and height (h) of circular pin-fin on the local fluid flow and heat transfer characteristics at Reynolds number (Re) of 398 and the average fluid flow and heat transfer characteristics with Re ranging from 133 to 530 in the IMCDCP are investigated using numerical simulation. In addition, to compare with the performance of IMCDCP, the smooth microchannel (SMC), the interrupted microchannel (IMC) and the interrupted microchannel with single circular pin-fin in each microchamber (IMCSCP) are also numerically investigated. These results show that using double circular pin-fins in each microchamber is an effective method in improving heat transfer performance. It effectively reduces the local wall temperature deterioration and achieves better wall temperature uniformity for the interrupted microchannel. The analysis results of geometric parameter show that pin-fin spacing plays an important role in the wall temperature uniformity, and proper pinfin height is in favor of heat transfer enhancement and pressure drop reduction. The assessment result of overall thermal performance shows optimum geometric parameters for the IMCDCP with h = 0.08 mm, d1 = d2 = 0.12 mm, s = 0.55 mm at Re = 530, yielding 42% enhancement as compared to SMC.