THERMO-HYDRAULIC CHARACTERISTICS IN GEOMETRICALLY MODIFIED MANIFOLD MICROCHANNEL HEAT SINKS: A NUMERICAL INVESTIGATION

Microchannel cooling effectively manages high heat flux in high-performance computing devices but may suffer from increased pressure drops, requiring more pumping power. The manifold microchannel heat sink (MMCHS) can ease this problem by managing simultaneous fluid flow through multiple inlets and outlets, thereby enhancing heat-transfer performance and temperature uniformity compared to traditional microchannel heat sinks (TMCHS). This study examines various MMCHS designs, including a simple manifold microchannel heat sink (SMMCHS), a diverging bottom-wall manifold microchannel heat sink (DMMCHS), and a stepped bottom-wall manifold microchannel heat sink (StMMCHS). The overall thermo-hydraulic performance of these MMCHS configurations is compared with that of the TMCHS. Deionized water is used as the working fluid, with a total volumetric flow rate ranging from 70 to 210 ml/min. Copper serves as the solid substrate material, subjected to a uniform heat flux of 50 W/cm2 on the bottom surface of the substrate. The results indicate that all MMCHS configurations significantly reduce pressure drop by up to 84.9%, decrease thermal resistance by a maximum of 38.2%, and improve temperature distribution uniformity compared to the TMCHS. However, the performance of modified MMCHS configurations is similar to that of SMMCHS. At a particular pumping power of 0.0015 W, the thermal resistance of the SMMCHS, DMMCHS, and StMMCHS is reduced by 51, 52.1, and 52.3%, respectively, compared to the TMCHS. Additionally, it is suggested that these modified MMCHS configurations could enhance two-phase flow boiling heat-transfer performance compared to the SMMCHS, which will be the focus of our future research.