Effect of Wavy Wall and Plate Bifurcations on Heat Transfer Enhancement in Microchannel

Abstract

Miniaturization of electronic components requires compact and effective cooling techniques to dissipate large heat flux without a significant increase in pumping power. Microchannel heat sink with liquid as working fluid is a suitable technique for the purpose. In this study, heat transfer characteristics in presence of vertical bifurcation placed downstream of the microchannel passage are studied numerically. Six types of bifurcating plates are considered under two categories: (i) thick-plate and (ii) wavy thin-wall. Water is taken as the working fluid and the flow rate has been varied in the Reynolds number range, 100 ≤ Re ≤ 1000. The effect of bifurcations on pressure drop, heat transfer, and the overall thermal resistance are analyzed and compared with those of plane microchannel without bifurcation. The numerical results show that the usage of bifurcation in the microchannel reduces the overall thermal resistance. Field synergy number, entropy generation number, and hydrothermal performance index are calculated to quantify the overall performance improvement in the microchannel with bifurcations. Constant wavy thin-wall bifurcation has been found to improve the overall performance of the microchannel. The detailed geometry of the bifurcation, the resulting convective heat transfer characteristics, and percentage improvement in the performance are reported.