Collaborative Research: ISS: Probing Interfacial Instabilities in Flow Boiling and Condensation via Acoustic Signatures in Microgravity

合作研究：ISS：通过微重力下的声学特征探测流动沸腾和冷凝中的界面不稳定性

• 批准号: 2323022
• 负责人: Han Hu
• 金额: $ 22.5万
• 依托单位: University of Arkansas
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2023
• 资助国家: 美国
• 起止时间: 2023-08-01 至 2026-07-31
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2323022&HistoricalAwards=false
• 关键词: Collaborative; Research; ISS; Probing; Interfacial

Flow boiling and condensation are crucial to the efficient and safe operation of electronics cooling, power generation, refrigeration, water purification, chemical processing, and among others. Two-phase flows are also subject to a wide range of instabilities at the liquid-vapor interface. These instabilities can lead to significant thermal performance degradation, reducing heat transfer coefficient, increasing pressure drop, and causing overheating. To prevent process disruptions or thermal performance deterioration, it is of utmost importance to enhance the understanding of instability mechanisms and continually monitor them. This project seeks to probe the physical mechanisms that dominate flow instabilities in microgravity using wideband acoustic emission (AE) sensing that measures and analyzes dynamic behaviors through acoustic waves. Two-phase flows are complex phenomena where many physical mechanisms simultaneously contribute to the measured signals, resulting in overlapping acoustic signatures and intrinsic noises during ground tests. The long-term microgravity environment on the International Space Station (ISS) inherently decouples the acoustic signatures of the physical mechanisms during two-phase flows and enables the examination of the leading transport mechanisms. The project team will also organize outreach events and create educational materials such as posters, brochures, podcasts, and videos to explain the advantages of research brought by the microgravity environment on ISS. This project aims to advance the fundamental understanding of the transport mechanisms that govern liquid-vapor interfacial instabilities in flow boiling and condensation using wideband AE sensing, with a focus on both the critical heat flux (CHF), the maximum achievable heat flux during flow boiling, and the flow regime transition during flow condensation. The project will fill this broad knowledge gap with three specific aims. First, a self-contained AE sensing module will be developed and benchmarked for individual transport processes including bubble departure, turbulence, and capillary flows in lab-scale tests before its deployment on ISS. Second, the role of interfacial waves and turbulent diffusion in flow condensation will be probed using both ground-based and microgravity flow condensation tests. The latter will be performed using the flow boiling and condensation experiment (FBCE) facility on ISS with the deployed acoustic sensing module. Third, the dominant transport mechanism during flow boiling flow regime transition and CHF will be examined. This project will provide valuable insights into interfacial instabilities of flow boiling and condensation, which are critical to the design and optimization of condensers and boilers that maximize heat transfer and minimize energy consumption. This project will make an impact on power generation, semiconductor manufacturing, chemical processing, and decarbonization of transportation.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.

流动沸腾和冷凝对于电子冷却、发电、制冷、净水、化学处理等的高效和安全运行至关重要。两相流动在气液界面处也会受到各种不稳定性的影响。这些不稳定性会导致热工性能显著下降，降低换热系数，增加压降，并导致过热。为了防止过程中断或热性能恶化，提高对不稳定机理的理解并对其进行持续监测至关重要。该项目旨在利用宽带声发射(AE)传感技术，通过声波测量和分析流体的动态行为，来探索在微重力条件下支配流动不稳定性的物理机制。两相流是一种复杂的现象，其中许多物理机制同时作用于测量信号，导致在地面测试过程中产生重叠的声学特征和本征噪声。国际空间站(空间站)上的长期微重力环境固有地使两相流动期间物理机制的声学特征分离，并使研究主要的传输机制成为可能。项目组还将组织外联活动，并制作海报、小册子、播客和视频等教育材料，解释国际空间站微重力环境带来的研究优势。本项目旨在利用宽带声发射传感技术促进对流动沸腾和冷凝过程中气液界面不稳定性的传输机制的基本理解，重点关注流动沸腾过程中的临界热流密度(CHF)、流动沸腾过程中的最大可达到热流密度以及流动冷凝过程中的流型转变。该项目将通过三个具体目标来填补这一广泛的知识缺口。首先，将开发一个独立的声发射传感模块，并在将其部署在国际空间站之前，在实验室规模的测试中对包括气泡离开、湍流和毛细管流在内的各个传输过程进行基准测试。其次，将通过地面和微重力流动凝结试验来探讨界面波和湍流扩散在流动凝结中的作用。后者将利用国际空间站上的流动沸腾和冷凝实验(FBCE)设施以及部署的声波传感模块进行。第三，考察了流动沸腾流型转变和CHF过程中的主要输运机制。该项目将对流动沸腾和冷凝的界面不稳定性提供有价值的见解，这对于设计和优化最大化传热和最小能耗的冷凝器和锅炉至关重要。该项目将对发电、半导体制造、化学加工和交通运输的脱碳产生影响。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。