A numerical study of forced convective flow in microchannels heat sinks with periodic expansion-constriction cross section
1MECACOMP Laboratory, Department of Mechanical Engineering, Tlemcen University, Tlemcen, Algeria
2ETAP Laboratory, Department of Mechanical Engineering, Tlemcen University, Tlemcen, Algeria
J Ther Eng 2018; 4(3): 1912-1925
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Abstract

This paper aims to study numerically the laminar convective heat transfer of ionized water flow inside rectangular heat sinks with periodic expansion-constriction cross-section; each heat sink consists of parallel microchannels system with 4 mm wide and 0.1 mm deep in constant cross-section segment. Two-dimensional laminar numerical simulations, based on Navier-Stoks equations and energy equation, are obtained under the same boundary conditions for different microchannels. In this study, the heat transfer and pressure drop inside microchannels with cross-section (cylindrical grooves and triangular cavities) are compared with that of simple smooth microchannel at Reynolds number ranging from 150-1500; an increase in pressure drop of 44% for all microchannels is observed with Reynolds number increasing. The obtained results indicate an enhancement in Nusselt number for all microchannels at all Reynolds number values with a maximum enhancement of 36%, these ameliorated thermal parameters attribute to enhance the heat transfer efficiency of proposed microchannels. Which improve the effect of periodic expansion-constriction cross-section on the heat transfer performance for microelectromechanical systems (MEMS) cooling phenomena.