Nucleate boiling is perhaps one of the most efficient cooling methodologies due to its large heat flux with a relatively low superheat. Nucleate boiling often occurs on surfaces oriented at different angles; therefore, understanding the behavior of bubble growth on various surface orientations is of importance. Despite significant advancement, numerous questions remain regarding the fundamentals of bubble growth mechanisms on oriented surfaces, a major source of enhanced heat dissipation. This work aims to accurately measure three-dimensional (3D), space- and time-resolved, local liquid temperature distributions surrounding a growing bubble on oriented surfaces that quantify the heat transfer from the superheated liquid layer during bubble growth. The dual tracer laser-induced fluorescence thermometry technique combined with high-speed imaging captures transient 2D temperature distributions within a 0.3 ºC accuracy at a 30 μm resolution. The results show that the temperature close to the heated surface and bubble interface exhibits an acute transient behavior at the time of bubble departure, and the growing bubble works as a pump to remove heat from the surface with a temperature difference of up to 10 °C during its growth and departure. The experimental results are compared with data available in the literature to validate the accuracy of the technique. It was found that the heat transfer coefficient close to the bubble interface and heater is approximately 1.3 times higher than the heat transfer coefficient in the bulk liquid.

中文翻译：

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双示踪剂激光诱导荧光测温，用于了解定向表面上核沸腾过程中的气泡生长

泡核沸腾可能是最有效的冷却方法之一，因为它具有较大的热通量和相对较低的过热度。泡核沸腾通常发生在不同角度的表面上；因此，了解气泡在不同表面方向上生长的行为非常重要。尽管取得了重大进展，但关于定向表面上气泡生长机制的基本原理仍然存在许多问题，这是增强散热的主要来源。这项工作的目的是精确测量定向表面上生长的气泡周围三维 (3D)、空间和时间分辨的局部液体温度分布，从而量化气泡生长过程中过热液体层的传热。双示踪激光诱导荧光测温技术与高速成像相结合，以 30 μm 的分辨率捕获 0.3 ℃ 精度内的瞬态二维温度分布。结果表明，气泡离开时受热表面与气泡界面附近的温度表现出剧烈的瞬态行为，不断长大的气泡起到泵的作用，以高达10℃的温差从表面带走热量。在它的成长和离开的过程中。将实验结果与文献中的数据进行比较，以验证该技术的准确性。结果发现，靠近气泡界面和加热器的传热系数比本体液体中的传热系数高约1.3倍。