Experimental and numerical investigation into the influence of connecting channel structures on flow and heat transfer characteristics within microchannels

With the continuous increase in power density and integration of electronic devices, thermal management systems are subject to increasingly stringent heat dissipation requirements. Microchannel heat sinks are a promising solution due to their compact structure and high heat transfer efficiency. However, the thermal performance of parallel microchannel heat sinks is often constrained by severe flow maldistribution and temperature non-uniformity, which degrade overall heat transfer performance. PIV technology offers certain advantages in terms of resolution and measurement accuracy; however, there is currently a gap in research regarding the use of PIV technology to observe flow characteristics inside channels and perform non-uniform optimization. In this study, the flow and heat transfer characteristics in a single-layer rectangular microchannel were investigated using Micro-PIV experiments and numerical simulations in the Reynolds number range of 50–600. The results show that as the inlet flow velocity increases, the flow velocity within the central channel becomes significantly higher than that in the peripheral channels, whilst the temperature is markedly lower than in the peripheral channels. To address this issue, a novel biomimetic dual-layer microchannel heat sink incorporating interconnecting channels was proposed. The interconnecting channels enable lateral fluid redistribution among adjacent channels, significantly improving flow uniformity and thermal performance. Compared with conventional microchannels, the proposed structure reduces flow non-uniformity by up to 39.6% and enhances the comprehensive thermal performance by as much as 58.5%. Therefore, the introduction of interconnecting channels provides an effective approach for improving temperature uniformity and heat dissipation capability in high-heat-flux electronic cooling applications.