Liquid cooling is an efficient way to remove heat fluxes with magnitudes up to 10,000 W/cm~2.One limitation of single-phase microchannel heat transfer is the relatively low Nusselt number, due to laminar flow. Several methods have been used to improve the Nusselt number such as geometric obtrusions, pins and fins and nanofluids. In this talk, we experimentally investigate the heat transfer enhancement of a heat sink where air bubbles are periodically injected. The segmented flow pattern generates recirculation loops that enhance transport phenomena. We show that segmented flow can enhance the Nusselt number of laminar flows in short channels by a factor two. Also, we demonstrate a simple and high-throughput method for removing bubbles from microchannels, using a hydrophobic porous membrane. The role of the thin liquid film coating the bubbles in the heat transfer and the bubble removal is investigated.
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机译：液体冷却是去除热通量高达10,000 W / cm〜2的有效方法。
由于层流，单相微通道传热的一个限制是相对较低的努塞尔数。已经使用了多种方法来改善Nusselt数，例如几何形状的凸起，大头针和鳍以及纳米流体。在本次演讲中，我们将通过实验研究周期性注入气泡的散热器的传热效果。分段的流型会产生再循环回路，从而增强传输现象。我们表明，分段流动可以将短通道内层流的Nusselt数量提高两倍。此外，我们演示了使用疏水性多孔膜从微通道中去除气泡的简单且高通量的方法。研究了液体薄膜包覆气泡在热传递和气泡去除中的作用。
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