Collaborative Research: Interfacial Instability, Convective Motion and Heat Transfer in Evaporating Films

合作研究：蒸发膜中的界面不稳定性、对流运动和热传递华盛顿大学和密歇根理工大学这个项目将研究蒸发薄膜的行为。特别值得关注的是由蒸发引起的流体表面和膜内流体运动的扰动，以及这些扰动如何影响膜结构和热传递。这些薄膜的主要考虑因素包括浮力、表面张力的差异以及蒸发造成的质量损失。通过改变实验条件，包括向蒸发膜提供热量的方式，系统地研究这些机制的作用。实验将在压力调节测试室中使用纯测试液进行。通过改变薄膜上温差的大小以及改变温差的方向来研究具有不同热条件的薄膜。每种热边界条件将在薄膜内产生不同的温度分布，对薄膜内的流体运动有不同的影响。蒸发膜将通过高速成像、膜内温度和壁面换热的测量以及膜厚度的超声波测量来研究。蒸发膜的行为也将用线性稳定性理论来检验。这项研究有望增进对基本蒸发过程的理解。这项研究的两个非常重要的实际应用是半导体材料中的晶体生长和磁存储设备中的表面织构。这项拟议的研究还将影响华盛顿大学(UW)和密歇根理工大学(MTU)的教育、招聘和推广计划。例如，超声波和诊断技术将被引入到华盛顿大学现有的航空航天主要实验方法课程中。

Collaborative Research: Interfacial Instability, Convective Motionand Heat Transfer in Evaporating FilmsUniversity of Washington and Michigan Technological University This program will study the behavior of thin, evaporating films. Of specific interest are the disturbances at the fluid surface and the fluid motion within the film caused by evaporation, and how these disturbances impact the film structure and the heat transfer. Key considerations in these films include buoyancy, differences in surface tension, and mass loss due to evaporation. The action of these mechanisms will be systematically studied by varying the conditions of the experiment, including the fashion in which the heat is supplied to the evaporating film. Experiments will be conducted using pure test fluids in a pressure-regulated test cell. Films with different thermal conditions will be studied by varying both the magnitude of the temperature difference across the film, as well as changing the direction of this temperature difference. Each thermal boundary condition will yield different temperature profiles within the film, with different impacts on the fluid motion within the film. The evaporating films will be studied by high-speed imaging, measurement of the temperature within the films and the heat transfer at the wall, and ultrasonic measurements of the film thickness. The behavior of evaporating films will also be examined using linear stability theory. This research is expected to lead to an improved understanding of fundamental evaporation processes. Two very important practical applications of this research are the growth of crystals in semiconductor materials and the texturing of surfaces in magnetic storage devices. The proposed research will also impact the education, recruiting, and outreach programs at the University of Washington (UW) and Michigan Technological University (MTU). For example, the ultrasound and diagnostic technique will be introduced into existing primary experimental methods courses in Aeronautics and Astronautics at the UW.