Numerical study on a new manifold ring-shaped microchannel structure for circular heat source with excellent temperature uniformity

The manifold microchannel heat sink shows great potential for cooling high-heat-flux electronic equipment owing to its exceptional thermal and flow performance. A new manifold ring-shaped channel design is introduced to improve the temperature uniformity for circular heat sources. A comparative analysis of the manifold straight channel, radial expansion channel and manifold ring-shaped channel designs is conducted based on the same heating area under equal mass flow conditions by numerical investigation using single-phase de-ionized water. The flndings indicate that the newly proposed manifold ring-shaped channel design exhibits a lower maximum temperature, a lower average temperature, a better temperature uniformity and a smaller pressure drop in comparison to the straight channel and radial channel designs. Speciflcally, at a mass flow rate of 2.5 g/s, the ring-shaped channel design demonstrates a 71.4 % and 45.4 % reduction in the temperature difference between the maximum temperature and the minimum temperature of the heating surface, and the coefflcient of performance is enhanced by 458.2 % and 169.7 % when compared to the straight channel and radial channel designs, respectively. Additionally, three improved designs based on the original manifold ring-shaped channel design are proposed to further enhance fluid flow distribution in the ring-shaped channel design. The results reveal that all three manifold ring-shaped channel optimizations further lower the maximum temperature, the average temperature and the temperature difference. Notably, the improved case3 exhibits the best thermal and hydraulic performances among all structures. When compared to straight channel and radial channel designs, the improved case3 demonstrates an 86.9 % and 75.0 % reduction in the temperature difference, and an increase of 201.2 % and 523.4 % in coefflcient of performance under the equal mass flow comparison basis. A heat flux of 1200 W/cm 2 can be dissipated at 6 g/s when the maximum temperature rise is kept below 60 K, with a pressure drop of 38 kPa.