Numerical investigation on heat transfer and flow mechanism in microchannel heat sink having V shape ribs

Abstract

This research comprehensively examines the influence of the V-shaped rib angle of attack on the thermal and hydraulic efficacy of microchannel heat sinks (MCHS), employing Computational Fluid Dynamics (CFD) simulations over Reynolds numbers ranging from 100 to 900. The primary innovation of this investigation resides in the methodical analysis of the impacts of varying rib angles, specifically from 35° to 90°, on both heat transfer and flow resistance within the MCHS framework. The findings indicate that a reduced angle of attack, notably 35°, markedly improves thermal performance, as evidenced by the Nusselt number (Nu) achieving a value of 13.81 at a Reynolds number of 300, in contrast to a mere 8.12 at 90°. This enhancement in thermal transfer is ascribed to the more effective turbulence produced at lower angles, which optimizes convective heat transfer while minimizing excessive resistance. Importantly, this study also underscores the dual effect of rib angle on flow dynamics, as diminished angles elevate friction factor (f), necessitating increased energy input for fluid movement—friction factor at a Reynolds number of 300 were recorded at 0.0465 for 35° and 0.0288 for 90°, thereby validating the compromise between heat transfer and flow resistance. This research offers a novel perspective that while elevated rib angles (approaching 90°) mitigate hydraulic resistance, they concurrently reduce the enhancement of heat transfer, thereby accentuating the necessity for an optimized rib angle to achieve equilibrium between thermal and hydraulic performance.