A holistic approach to thermal-hydraulic design of 3D manifold microchannel heat sinks for energy-efficient cooling

Abstract

Manifold microchannel heat sinks (MMCHSs) have attracted attention for the thermal management of high-performance electronics owing to their high heat dissipation rate and low pressure drop compared to conventional microchannels. This study used a full 3D conjugated simulation to analyze the effects of changes in the geometry and operating environment on the thermal and hydraulic performance of MMCHS. The findings provide a holistic view of MMCHS design for performance improvement. Twelve manifold geometries were designed by changing the direction and width of the manifold outlet in each case. Using water as the working fluid, we evaluated each manifold's thermal and hydraulic performance in the flow rate range of 100–500 g/min, and compared their thermal resistances per unit pumping power to determine the most efficient manifold structure for each operating environment. Compared to a conventional microchannel, the MMCHS reduced the thermal resistance by up to 47% and the pressure dropped by up to 90%, depending on the geometry. The thermal performance index (TPI), which relates thermal performance to pressure drop, was improved by 139% in the current MMCHS design over the TPI of a conventional microchannel. This sizeable improvement resulted from the excellent temperature uniformity and shortened the fluid flow path in the microchannel.

Keywords

• Thermal management
• Manifold microchannel
• Thermal performance index
• Electronics cooling