High heat transfer coefficient (HTC) and critical heat flux (CHF) are achieved in liquid film boiling by coupling vibrant vapor bubbles with a capillary liquid film, which has thus received increased interest for thermal management of high-power electronics. Although quite some experimental progresses have been made, there lacks a high-fidelity heat transfer model for liquid film boiling. This work develops a thermal-hydrodynamic model by considering both evaporation atop the wick and nucleate boiling inside the wick to simultaneously predict the HTC and CHF. Nucleate boiling is modeled with microlayer evaporation theory, where a unified scaling factor is defined to characterize the change of microlayer area with heat flux. The scaling factor η is found to be independent of wicking structure and can be determined from a few measurements. This makes our model universal to predict the liquid film boiling heat transfer for various micro-structured surfaces including micropillar, micropowder, and micromesh. This work not only sheds light on understanding fundamental mechanisms of phase-change heat transfer, but also provides a tool for designing micro-structured surfaces in thermal management.

中文翻译：

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微结构表面液膜沸腾的传热模型

通过将充满活力的蒸汽泡与毛细管液膜耦合，在液膜沸腾中实现高传热系数（HTC）和临界热通量（CHF），因此人们对高功率电子设备的热管理越来越感兴趣。尽管已经取得了相当多的实验进展，但缺乏高保真度的液膜沸腾传热模型。这项工作通过考虑吸芯顶部的蒸发和吸芯内部的核沸腾来开发热流体动力学模型，以同时预测 HTC 和 CHF。采用微层蒸发理论对核沸腾进行建模，定义统一的比例因子来表征微层面积随热通量的变化。发现比例因子 η 与芯吸结构无关，并且可以通过一些测量来确定。这使得我们的模型能够通用地预测各种微结构表面（包括微柱、微粉和微网）的液膜沸腾传热。这项工作不仅有助于理解相变传热的基本机制，而且还为设计热管理中的微结构表面提供了工具。