Research Initiation Award: Visualization of Surface Temperature Distributions in Incipient Boiling Using Liquid Crystal Thermography

本项目使用随时间变化的液晶热成像技术来捕捉介电流体中初始池现象的图像。结果集中在两个问题上：温度在受热表面的分布，以及初沸现象固有的瞬态性质。该技术产生表面温度分布的时间序列图像。这些图像显示了系统接近、通过并维持核池沸腾时的表面温度模式。特别令人感兴趣的是瞬时过程，在此过程中，成核位置被激活并在数量上增长以取代单相对流。研究了表面制备、流体过冷和溶解气体含量的影响。结果包括实时彩色图像，以及对选定配置的空间平均表面温度和表面温度光谱的测量。

This project uses time-dependent liquid crystal thermography to capture images of the incipient pool phenomenon in dielectric fluids. The results focus on two issues: the distribution of temperature across the heated surface, and the inherently transient nature of the incipient boiling phenomenon. The technique produces a temporal sequence of images of the surface temperature distribution. These images show the surface temperature patterns as the system approaches, passes through, and sustains nucleate pool boiling. Of particular interest is the transient process by which the nucleation sites activate and grow in number to displace the single-phase convection. The effects of surface preparations, fluid subcooling, and content of dissolved gases will be investigated. The results include real-time color images, and measurements of the spatial-averaged surface temperature and surface temperature spectra for selected configurations.