Effects of structural parameters on fluid flow and heat transfer in a serpentine microchannel with fan-shaped reentrant cavities

Abstract A three-dimensional numerical model has been conducted to study the laminar flow and heat transfer characteristics in serpentine microchannel with different geometric fan-shaped reentrant cavities for Reynolds number ranging from 150 to 980. The microchannel has the width of 0.1 mm and depth of 0.2 mm in the rectangular cross-section. The geometric parameters of fan-shaped reentrant cavities examined in this paper are 0.04058 mm for the width ( W c ), 0.0084–0.02029 mm for the height ( H c ) and 0.04058–0.12174 mm for the spacing ( S c ). This study firstly presents the comparison of the thermal and hydraulic characteristics of serpentine microchannel with fan-shaped reentrant cavities with the conventional microchannels heat sink. Then the effects of fan-shaped cavities on velocity contour, temperature distribution and secondary flow features in such microchannel heat sinks are given. It is apparent that the fan-shaped cavities can effectively reduce the flow resistance and improve the temperature distribution uniformity. The effects of developed non-dimensional variables on the frictional pressure drop, average Nusselt number and the relationship between thermal resistance and pumping power in the novel channel are investigated. Compared with rectangular serpentine channel, heat transfer is enhanced for all cases and flow resistance is decreased besides Re  = 980 and H c / W c  = 0.2887. The best performance of serpentine microchannel with fan-shaped reentrant cavities is found at S c / W c  = 3 and H c / W c  = 0.2887.