Abstract:
The increasing demand for efficient cooling solutions in high-performance electronics highlights the critical role of microchannel heat sinks (MCHS) with interconnected channels for advanced thermal management. Despite advancements, limited research has explored the influence of interconnectors design 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 orthogonal and oblique interconnectors, using HFE-7100 as the working fluid, focusing on enhancing heat transfer and optimizing hydraulic performance. The investigation utilized the Lee mass transfer model and the Volume of Fluid (VOF) approach to capture phase-change dynamics and two-phase flow behavior under varying mass fluxes (280.4–1121.6 kg/m2s) and heat fluxes (40–60 W/cm2). Nine geometric configurations were analyzed and compared against a baseline parallel microchannel design, varying interconnector width and orientation while maintaining a constant aspect ratio of 1.
The interconnectors promoted continuous thermal boundary layer disruption and improved mixing, reducing pressure drop penalties. Key findings revealed two distinct flow regimes: suction-induced flows that enhanced thermal performance and disruptive flows that impaired it. Practical designs use the mix of these two types, where both types of flow field co-exist. Case with 45° orientation and 50 μm interconnector width demonstrated superior performance, achieving a ~28% higher heat transfer coefficient and ~23% lower thermal resistance relative to the baseline, though with a ~15.5% increase in pressure drop. Conversely, Case with 135° and 100 μm interconnector width demonstrated reduced performance, achieving a ~15% lower heat transfer coefficient and ~14% higher thermal resistance relative to the baseline, with a ~19% decrease in pressure.
These enhancements facilitated the effective dissipation of high heat fluxes while balancing the pumping power requirements. The study provides a comprehensive analysis of flow phenomena through contour visualizations of vapor fraction and velocity fields, as well as plots of thermal resistance, heat transfer co-efficient, wall superheat and other parameters, and flow instabilities emphasizing the critical influence of interconnector orientation and geometry. These findings underscore the potential of interconnectors design in balancing thermal and hydraulic performance and offer valuable design guidelines for the development of next-generation MCHS for high-performance thermal management applications.