Boiling Heat Transfer at the Vicinity of 3-Phase Interface by Direct Comparison between Flow Behavior and Temperature Distribution on the Heated Surface

微间隙通道内的沸腾和两相流动是近年来在电子器件热管理应用中提出的一种直接冷却热源的方法。本文利用温敏涂料(TSP)对微缝隙加热表面的沸腾换热和气液两相流动进行了实验研究。实验是在单个矩形通道中进行的，微间隙宽度为10 mm，加热长度为35 mm，高度为0.5 mm。在被加热的壁面上涂覆的TSP被用来获得局部温度和随后的局部传热系数。FC-72的流速为200 mg/S，以339K的热水为热源沸腾试液。TSP可同时实现气液两相行为的观察和受热面温度分布的测量。结果表明，沸腾气泡背面的热流密度是气泡正面热流密度的1.2-1.5倍。

Boiling and Two-phase flow in microgap channel has been recently proposed for cooling the heat sources directly in application of thermal management for electronic devices. In this study, the boiling heat transfer and gas-liquid flow on the heated surface in microgap is investigated experimentally by using Temperature-Sensitive Paint (TSP). Experiments are performed in a single rectangular channel having microgap of 10 mm width, 35 mm heated length and 0.5 mm height using FC-72. TSP coated on the heated wall is used to obtain the local temperatures and subsequently local heat transfer coefficients. Flow rate of FC-72 is 200 mg/s and heated water at 339 K is used as a heat source for boiling of the test fluid. Observation of gas-liquid behavior and measurement of the temperature distributions on the heated surface could be achieved at the same time by TSP. As a result, the heat flux of the rear side of a boiling bubble is 1.2-1.5 times higher than that of the front side of a bubble.