Computational study on the thermo-fluidic performance of manifold microchannels with circular and square pin fins in cold plates for data centre cooling

Efficient thermal management of high-power electronic devices is a major challenge in hyperscale datacentres, where manifold microchannel (MMC) cold plates have emerged as a promising direct liquid-cooling solution. In this study, a three-dimensional conjugate heat-transfer numerical investigation is performed to evaluate the thermo-fluidic performance of pin–fin-integrated MMC cold plates. Circular and square pin fins are introduced in place of a bifurcation-based baseline configuration, and the effects of pin–fin geometry, arrangement (inline and staggered), and fin count are systematically surface area constraint. This framework enables the influence of flow redistribution and effective surface utilization to be analysed independently of total heat-transfer area variation. Performance is evaluated in terms of thermal resistance, pressure drop, and cooling coefficient of performance (COP). Results show that circular pin fin configurations generally provide lower thermal resistance than square pin fin configurations. A flow-rate-dependent crossover behaviour is observed between inline and staggered arrangements, where staggered configurations exhibit superior thermal performance at moderate to high flow rates despite increased pressure drop. Among all configurations, the staggered circular pin–fin configuration with 7 fins demonstrates the most favourable overall thermo-fluidic performance, providing the lowest thermal resistance together with comparatively high COP. These findings demonstrate the strong potential of optimized pin–fin-based MMC cold plates for energy-efficient cooling of next-generation GPUs in hyperscale datacentres.