Investigation of Enhanced Hydrothermal Performance With Flow Switching Configuration in Double-Layered Microchannel Heat Sink

Abstract The paper proposes the unique flow switching configurations (FC4 and FC5) of a double-layered microchannel heat sink (DL-MCHS). Their hydrothermal performances are compared with conventional design configurations such as concurrent (FC1), countercurrent (FC2), U-shaped (FC3), flow confinement without flow switching (FC6), and flow switching without confinement (FC7). The numerical simulations solve the conjugate heat transfer problem for seven different design configurations under the Re number range of 50–200. In addition to thermal resistance (R), pressure drop (△P), thermal performance (TP), and maximum temperature (Tmax), this study also uses the two thermodynamic variables, such as thermal entropy (St) and frictional entropy (Sf), as performance metrics. The results reveal that FC5 exhibits the lowest thermal resistance with the highest pressure drop value for all the Re numbers. However, the high value of TP for FC5 demonstrates the dominance of thermal benefit against pressure drop penalty. Furthermore, the lower thermal entropy of FC5, among the other configurations, indicates its uniform temperature distribution. The study also explores the impact of flow-switching locations on the overall thermal characteristics of FC4 and FC5. The optimized thermal performance with a uniform temperature gradient of FC4 and FC5 is obtained at Lc = 6.5 mm and Ld = 6 mm, respectively.