The purpose of this paper is to demonstrate the possibility to selectively tune the convective heat transfer coefficient in different sections of a heat sink by varying the density of micro-features in order to minimize temperature gradients between discrete heat sources positioned along the flow path. Lifetime of power electronics is strongly correlated to the thermal management of the junction. Therefore, it is of interest to have constant junction temperatures across all devices in the array. Implementation of micro-feature enhancement on the convective side improves heat transfer due to an increase in surface area. Specific shapes such as micro hydrofoils offer a reduced pressure drop allowing for combined improvement of heat transfer and flow performance. This study presents experimental results from an array of three discrete heat source (20 × 15 mm) generating 100 W/cm~2 and positioned in line along the flow path with a spacing of 10 mm between each of the sources. The heat sink was machined out of aluminum 6061 and micro-hydrofoils with a characteristic length of 500 μm were embedded in the cold plate. The cooling medium used is water at a flow rate of 3.6 - 13.4 g/s corresponding to a Reynolds number of 420 - 1575. It is demonstrated that the baseplate temperature can be maintained below 90°C and the difference between the maximum temperatures of each heat source is less than 6.7 °C at a heat flux of 100 W/cm~2 and a water flow rate of 4.8 g/s.
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机译：本文的目的是演示通过改变微特征的密度，以最小化沿流动路径放置的离散热源之间的温度梯度，来有选择地调整散热器不同部分中对流传热系数的可能性。电力电子设备的使用寿命与结的热管理密切相关。因此，关注阵列中所有器件的结温恒定。在对流侧实现微特征增强可提高表面积导致的热传递。诸如微型水翼之类的特定形状提供了降低的压降，从而可以同时改善传热和流动性能。这项研究提出了一组由三个离散热源（20×15 mm）产生的实验结果，该热源产生100 W / cm〜2的温度，沿着流路排成一行，每个热源之间的间距为10 mm。用铝6061机加工出散热器，并将特征长度为500μm的微型水翼嵌入冷却板中。所用的冷却介质是水，流速为3.6-13.4 g / s，对应于雷诺数为420-1575。证明了基板温度可以保持在90°C以下，并且每种温度的最高温度之差当热通量为100 W / cm〜2，水流量为4.8 g / s时，热源温度低于6.7°C。
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