Independent microscale sensing of phase interface and surface temperature during droplet evaporation
Independent microscale sensing of phase interface and surface temperature during droplet evaporation
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DOI：
10.1016/j.applthermaleng.2023.121477
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发表时间：
2023-09-09
影响因子：
6.4
通讯作者：
Moore，Arden L.
中科院分区：
文献类型：
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作者：
Mondal，Md Tanbin Hasan;Hossain，Rifat-E-Nur;Moore，Arden L.
尽管蒸发换热现象具有重要和普遍的性质，但关于发生在表面上单个液滴内部和周围的微观过程仍然存在基本问题。为了了解蒸发换热背后的物理基础，在单个液滴水平上获得关于表面温度随时间的分布以及移动的多相接触线(MCL)的位置和速度的信息是至关重要的。在这项工作中，利用由电阻加热器、空间分布的薄膜电阻温度探测器阵列和相界面传感电容微传感器阵列组成的多功能微尺度装置，同时测量了水平加热表面上单个固着水滴蒸发的局部换热特性和MCL行为。微器件基于电阻和电容的工作原理意味着，即使在能见度有限或没有能见度的应用中，例如在热管理硬件或处理设备中，它也能够在微尺度上实时检测温度变化和跟踪MCL。重要的是，在微尺度的精度下了解MCL的位置和速度，可以直接研究它对表面温度和热传递的影响，而不是推断。结果表明，MCL通道先于局地地表温度的变化，并且这些事件之间的时差持续时间取决于MCL的速度。此外，在蒸发过程中，MCL的通过占整个温度变化的70%以上。
Despite the important and pervasive nature of evaporative heat transfer phenomena, fundamental questions still remain about the microscopic processes that occur in and around individual droplets on a surface. In order to understand the underlying physics behind evaporative heat transfer, it is critical to have information at the individual droplet level regarding the surface temperature distribution with time as well as the location and speed of the moving multiphase contact line (MCL). In this work, a multifunctional microscale device comprised of a resistance heater, an array of spatially distributed thin-film resistance temperature detectors, and a phase interface sensing capacitance micro-sensor array has been utilized to measure the local heat transfer characteristics and MCL behavior simultaneously for the evaporation of individual sessile water droplets on a horizontal heated surface. The resistance- and capacitance-based operating principles of the micro-device means that it is capable of detecting temperature changes and tracking MCL at the microscale in real time even for applications with limited or no visibility such as within thermal management hardware or processing equipment. Importantly, having knowledge of the MCL’s location and speed with microscale precision allows for its influence on surface temperature and heat transfer to be directly studied rather than inferred. Results show that the MCL passage precedes the change in local surface temperature and the duration of the time difference between these events depends on the MCL’s speed. In addition, the passage of the MCL accounts for more than 70% of the overall temperature change during the evaporation process.