Collaborative Research: ISS: Understanding thermal transport across a condensing film by conducting experiments in microgravity

冷凝过程的利用可以为许多行业提供显著的能源效益，包括能源、航空航天、国防、消费电子、可再生能源和节水领域。然而，对影响这种冷凝过程的不同物理参数缺乏基本的了解，限制了这些系统的广泛实施。重力是强烈影响各种陆地系统凝结过程中能量传输的重要参数之一。然而，在实验室环境中，没有办法隔离重力。通过利用国际空间站上的冷凝设施进行测试，了解重力背后的物理原理及其对冷凝流动的影响是该项目的首要目标。对物理学的更好理解将导致更好地控制地面系统，并影响工程设计决策。与空气或液体单相系统相比，冷凝提高了系统效率，减少了系统占用空间。然而，设计有效的冷凝排热装置的障碍来自于对重力等参数对液-汽界面行为和相应的热传递的影响缺乏基本的了解。这项研究的中心假设是，如果重力是孤立的，界面波度和湍流对凝结膜内热输运的影响可以用实验和计算相结合的方法来捕捉。计划在国际空间站的流动沸腾和冷凝实验设施上进行利用冷凝模块进行换热的实验，并计划在地球重力条件下进行补充测试。此外，研究小组计划用高保真CFD模拟和建模来补充实验，以捕捉两相界面行为对热传输的影响。更广泛的影响目标是改进具有相变过程的热传输建模，从而帮助两相流和传热界开发适用于各种工业应用的高效冷凝器。在教育和推广计划中，该团队将为凯斯西储大学的S创新导论项目开发一个模块，并在凯斯西部储备大学和先进冷却技术之间建立一个联合的两相流动研讨会。该奖项反映了美国西部储备大学的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

The utilization of the condensation process can provide significant energy benefits to many industries including those in energy, aerospace, defense, consumer electronics, renewable energy, and water conservation. However, there is a lack of fundamental understanding of the different physical parameters impacting this condensation process limiting the widespread implementation of these systems. Gravity is one of those important parameters that strongly impact energy transport during the condensation process in various terrestrial systems of interest. However, there is no way of isolating gravity in laboratory settings. Understanding the physics behind gravity and its impact on condensing flow is the overarching goal of this project by performing testing utilizing the condensation facility onboard the International Space Station. A better understanding of physics will lead to better control of terrestrial systems and also impact engineering design decisions.Condensation increases system efficiency and reduces system footprint compared to air or liquid single-phase systems. However, the barrier to designing an efficient condensation heat rejection device stems from a lack of fundamental understanding of the influence of parameters like gravity on the liquid-vapor interfacial behavior and the corresponding thermal transport. The central hypothesis of this research is that if gravity is isolated, the impact of interfacial waviness and turbulence on thermal transport in the condensing film can be captured with an integrated experimental and computational approach. Experiments are planned to utilize the condensation module for heat transfer onboard the International Space Station’s Flow Boiling and Condensation Experiment facility and supplemental testing is planned in Earth gravity conditions. In addition, the research team plans to supplement the experiments with high-fidelity CFD simulations and modeling to capture the impact of the two-phase interfacial behavior on thermal transport. The broader impact objectives are to improve thermal transport modeling for processes with phase change, thus helping the two-phase flow and heat transfer community develop efficient condensers for a variety of industrial applications. In the education and outreach plan, the team will develop a module for Case Western Reserve University (CWRU)’s NSF-supported Introduction to Innovation program as well as set up a joint Two-Phase Flow Workshop between CWRU and Advanced Cooling Technologies.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.