CDS&E: Multiscale Data Intensive Simulation and Modeling of Microemulsion Boiling: A New Paradigm for Boiling Enhancement

正在开发新的大功率电子产品、制冷系统和发电设备，以彻底改变工业的技术基础。在这些应用中产生的过高水平的热量的消散是它们实际使用的根本瓶颈。解决这个问题的一种可能的方法是使用传热液体的沸腾，这种方法利用了将液体转化为蒸汽所产生的高能以及伴随而来的液体搅拌。然而，目前寻找高性能换热流体的研究主要依赖于经验试错法，并且主要集中在制冷剂的使用上。该项目的主要目的是探索微乳液作为沸腾液体的使用，并利用计算和实验相结合的方法创建一个合理的微乳液沸腾设计框架。本项目计划研究微乳沸腾强化的原因，以便在实际环境中进一步改进和部署微乳。该项目还将包括重要的教育和推广活动，包括少数民族学生和以微乳液沸腾实验和模拟为特色的科学艺术展示。该项目的目标是开发微乳液沸腾的全面图像，并利用这些信息设计用于热管理应用的新的和改进的微乳液。目前尚不清楚为什么微乳液沸腾在气泡的形成和生长过程中表现出很大的有序性和规律性，也不知道气泡是如何生长到非常大的尺寸但仍然附着在表面并在表面产生高热流密度的。该项目试图通过在密切协调的模拟和实验努力的基础上，为研究微乳沸腾创造一个合理的设计框架，以填补这一知识空白。模拟工作的重点是在最先进的开源、大规模并行、支持GPU的连续介质规模模拟框架上部署尖端的、高精度的计算方法(包括现有的和本项目中提出的新方法)。实验将被用来(I)指导新的计算方法和物理模型的发展，(Ii)使用匹配的实验条件来验证数值求解器，(Iii)制备具有数值模拟所建议的理想性能的新的微乳液，以及(Iv)最终验证使用新的微乳液对换热的预测强化。这种计算和实验相结合的方法将(I)阐明微乳液沸腾的新物理机制，(Ii)描述微乳液的哪些热物理性质需要调整以改善热性能，以及(Iii)在实验室设计具有理想热物理性质的新微乳液。这种方法有望在微乳液沸腾和电子/光电子、工业热交换器和分布式加热系统的冲击热管理方面产生前所未有的理解。该奖项反映了NSF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。

Novel high-power electronics, refrigeration systems and power generation equipment are being developed to revolutionize the technological foundations of industry. Dissipation of excessively high levels of heat generated in these applications is a fundamental bottleneck in their practical use. One potential method to resolve this issue is to use boiling of heat transfer fluids, which takes advantage of high energies associated with converting liquid to vapor and the accompanying liquid agitation. However, the current studies on the search for high performance heat transfer fluids rely mainly on empirical trial and error approaches and are focused on the use of refrigerants. The principal aim of this project is to explore the use of microemulsions as the boiling fluid, and to create a rational design framework for microemulsion boiling using an integrated computational and experimental approach. This project plans to study the causes of the enhancement in microemulsion boiling in order to further improve and deploy microemulsions in practical settings. The project will also encompass significant educational and outreach activities, involve minority students and art-in-science displays featuring microemulsion boiling experiments and simulations.The goal of this project is to develop a comprehensive picture of microemulsion boiling and use that information to design new and improved microemulsions for thermal management applications. It is currently not known why microemulsion boiling exhibits great order and regularity in bubble formation and growth and how bubbles grow to a very large size yet remain attached to the surface and still generate high heat fluxes at the surface. The project seeks to fill this knowledge gap by creating a rational design framework for studying microemulsion boiling based on closely coordinated simulation and experimental efforts. The simulation effort is focused on deploying leading edge, high accuracy computational methods (both existing and new methods proposed in this project) on a state-of-the-art open-source, massively parallel, GPU enabled continuum scale simulation framework. Experiments will be used to (i) guide the development of new computational methods and physics models, (ii) validate the numerical solver using matched experimental conditions, (iii) prepare new microemulsions with desirable properties suggested by the numerical simulations and (iv) finally validate the predicted enhancement in heat transfer using the new microemulsions. This integrated computational and experimental approach will (i) elucidate new physical mechanisms in microemulsion boiling, (ii) delineate which thermophysical properties of microemulsions need to be tuned for improved thermal performance, and (iii) engineer new microemulsions in the laboratory with desirable thermophysical properties. This approach is expected to yield unprecedented understanding on microemulsion boiling and impact thermal management of electronics/optoelectronics and industrial heat exchanger and distributed heating systems.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.