Flow and heat transfer characteristics of pin-fin microchannel heat sink with associated diversion structure

Abstract

Pin-fins microchannel heat sinks (PFMCHSs) demonstrate outstanding cooling performance for electronic devices. However, the flow dead zone formed behind the pin-fins remains critical drawbacks in practical applications. To address this issue, this study proposes an associated diversion structure (ADS) integrated into the PFMCHS. Three-dimensional simulation, validated against experimental data, was employed to elucidate the underlying enhancement mechanism. A parametric study systematically investigates the effects of the ADS height, horizontal and vertical distances relative to the pin-fins, and diameter on thermal and hydraulic characteristics. These results are compared to a conventional PFMCHS with pin-fins heigh, diameter and spacing of 1.0, 0.5 and 1.5 mm respectively under a reduced solid volume fraction. Results indicate that the incorporation of ADS effectively redirects fluid flow behind the pin-fins, thereby suppressing flow dead region and promoting cold and hot fluids mixing. The beneficial effect becomes increasingly pronounced with the decrease of vertical offset and increases of height, horizontal offset and diameter. The optimum ADS configuration achieves a 19.3–21.1% reduction in maximum temperature at inlet velocity range of 0.15–0.35 m/s, accompanied by 153.7–225.3% increase in pressure drop, and 1.84–1.97 times PEC compared to the conventional PFMCHS. Furthermore, within a pumping power range of 0.15–0.8 mW, thermal resistance of the optimal configuration is reduced by 20.8–22.2% compared to the conventional PFMCHS.