Laminar flow and heat transfer characteristics of interrupted microchannel heat sink with ribs in the transverse microchambers

The paper is focused on the investigation of the laminar flow and heat transfer characteristics in the interrupted microchannel heat sink with ribs in the transverse microchambers. A three-dimensional model based on finite volume approach and SIMPLEC algorithm is performed considering entrance effect, conjugate heat transfer, viscous heating and temperature-dependent thermo-physical properties. Five different rib configurations are considered, including rectangular, backward triangular, diamond, forward triangular and ellipsoidal. The present study firstly examines the effect of such ribs on velocity contour, pressure distribution and temperature distribution, further the local pressure drop and heat transfer characteristics in such microchannel heat sinks. Result shows that the ribs in the transverse microchambers can effectively prevent the decline of local heat transfer coefficient along the flow direction. Secondly, the average friction factor and Nusselt number for such microchannel heat sinks have been studied. Results show that for Reynolds number ranging from 187 to 715, there is a 24-57% increase in the Nusselt number for the interrupted microchannel heat sinks with ribs, while the friction factor increased by 3-70%, comparing with the straight microchannel heat sink. Finally, based on the performance evaluation criteria, the performance of such microchannel heat sink has been comprehensively evaluated. Results shows that for the studied Reynolds number range and microchannel geometries in this paper, the interrupted microchannel heat sink with ellipsoidal ribs in the transverse microchambers shows the best heat transfer performance, with maximum 1.39 of performance evaluation criteria. (C) 2016 Elsevier Masson SAS. All rights reserved.