Numerical analysis of thermal and hydraulic characteristics of flow boiling in oblique interconnected microchannel heat sinks

Abstract

The rising demand for efficient cooling solutions in high-performance electronics underscores the importance of microchannel heat sinks (MCHS) with interconnected channels for thermal management. Despite advancements, limited research has explored the influence of oblique interconnectors on flow distribution and their impact on optimizing thermal and hydraulic performance. This study addressed this gap by numerically investigating the hydrothermal behavior of interconnected MCHS with oblique interconnectors, using HFE-7100 as the working fluid. Six geometric configurations were compared to a baseline parallel microchannel design to determine the optimal interconnector size and orientation. The study employed the Lee mass transfer model and the Volume of Fluid (VOF) approach to capture phase-change dynamics and flow behavior under varying mass fluxes (280.4–1121.6 kg/m2s) and heat fluxes (40–60 W/cm2). The results revealed two distinct flow regimes: suction-induced flows that enhanced thermal performance and disruptive flows that impaired it. One particular design (Case 1) demonstrated superior performance with a ∼26 % higher heat transfer coefficient, ∼23 % lower thermal resistance, and a 12.45 K reduction in wall superheat relative to the baseline, though at the expense of a ∼14 % increase in pressure drop. These findings highlighted the critical role of interconnector orientation in balancing thermal and hydraulic performance, offering a design guideline for future innovations in microchannel heat sinks.