Novel thermal design of micro-bream-fin heat sink using contour-extraction-based (CEB) method

Abstract

This work proposes a novel method, namely contour-extraction-based (CEB) method, which extracts the wake flow contours in the channels as the geometry contours of the pin fin to enhance thermal and hydraulic performances of micro-pin-fin heat sink (MPFHS). By employing this method, a novel heat sink with bream-body-like fins, namely micro-bream-fin heat sink (MBFHS), is generated by improving the geometry of the micro-circular-fin heat sink (MCFHS). The fluid flow and heat transfer characteristics of the novel MBFHS are simulated using a conjugate 3D numerical model with RNG k-ε turbulence model which is analytically validated by the energy balance theory. The thermal and hydraulic performances of the novel MBFHS are evaluated in terms of the junction temperature, Nusselt number, friction factor, and overall performance indexes. It is found that MBFHS has a larger convection heat transfer surface area, a better fluid-solid interaction, a higher flow velocity, a better fluid mixing, and more solid materials compared to the conventional MCFHS, which all contribute to the enhancement in the heat transfer performance. And the promotion is more pronounced at high spacing ratios and Reynolds numbers. The pin convection performance of the novel bream fin could be up to 34% higher than that of the original circular fin, and the thermal resistance and bottom-wall temperature difference of MBFHS are lower by 26% and 38% than those of MCFHS, respectively.