CAREER: Active Cooling of Extreme Heat Fluxes via Transient Fluid Flow and Evaporation in Liquid Thin-films

职业：通过液体薄膜中的瞬态流体流动和蒸发主动冷却极端热通量

• 批准号: 1653396
• 负责人: Shawn Putnam
• 金额: $ 51万
• 依托单位: The University of Central Florida Board of Trustees
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2017
• 资助国家: 美国
• 起止时间: 2017-05-01 至 2022-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1653396&HistoricalAwards=false
• 关键词: CAREER; Active; Cooling; Extreme; Heat

Active Cooling of Extreme Heat Fluxes via Transient Fluid Flow and Evaporation in Liquid Thin-filmsThis project entails a research and educational program on transient heat and mass transport at liquid interfaces. Transient heat fluxes in cutting-edge technologies can exceed 50 MW/m2, which is nearly the heat flux radiated by the Sun. To manage extreme thermal loads, the State-of-the-Art is to boil and evaporate liquid coolants on micro- and nano-structured heat sinks. However, modern cooling techniques cannot manage extreme heat fluxes under transient conditions. Thermo-fluid transients due to on/off device operation or intermittent exposure to an extreme environment result in highly unstable thermo-fluid behavior, ultimately placing a liquid-cooled device in danger of catastrophic failure via thermal runaway -- i.e., a rapid, uncontrolled increase in device temperature.An integrated research-and-education program is pursued to broaden the institutional curriculum, training, and education on transient processes in modern technologies. A unique summer workshop and academic outreach activities will tap into several well-established STEM programs, facilitating the use of many educational elements -- including in-class projects, demos, videos, and discussions on transient operation and non-equilibrium processes. The technical objective is to identify the fundamental limits of evaporative heat transfer under transient conditions. The main approach is to test if the heat transfer coefficient (HTC) of evaporating thin-films follows the predictions of the kinetic theory of gases. The project will incorporate a combination of time-resolved optical diagnostics to characterize the transient HTC and its dependence on interrelated factors such as vapor quality, superheat, and changes in heater surface structure and chemistry. These transient investigations coupled with steady-state and quasi-steady experiments are expected to reveal previously unexposed key heat transfer processes, increasing both the awareness and knowledge of transient processes in modern technologies, which are vital for new ideas in renewable energy, advanced computing, and nanotechnology.

通过液体薄膜中的瞬态流体流动和蒸发来主动冷却极端热通量该项目需要开展关于液体界面瞬态热和质量传输的研究和教育计划。尖端技术的瞬态热通量可超过50 MW/m2，接近太阳辐射的热通量。为了管理极端的热负荷，最先进的技术是在微米和纳米结构散热器上沸腾和蒸发液体冷却剂。然而，现代冷却技术无法管理瞬态条件下的极端热通量。由于开/关设备操作或间歇性暴露于极端环境而导致的热流体瞬变会导致热流体行为高度不稳定，最终使液冷设备面临因热失控而导致灾难性故障的危险，即设备温度快速、不受控制地升高。正在实施一项综合研究和教育计划，以扩大有关瞬态过程的机构课程、培训和教育。 现代技术。独特的夏季研讨会和学术推广活动将利用多个成熟的 STEM 项目，促进许多教育元素的使用，包括课堂项目、演示、视频以及关于瞬态运行和非平衡过程的讨论。技术目标是确定瞬态条件下蒸发传热的基本极限。主要方法是测试蒸发薄膜的传热系数（HTC）是否符合气体动力学理论的预测。该项目将结合时间分辨光学诊断来表征瞬态 HTC 及其对蒸汽质量、过热度以及加热器表面结构和化学变化等相关因素的依赖性。这些瞬态研究与稳态和准稳态实验相结合，预计将揭示以前未公开的关键传热过程，提高现代技术中瞬态过程的认识和知识，这对于可再生能源、先进计算和纳米技术的新想法至关重要。

项目成果

Analysis of time-dependent heat transfer with periodic excitation in microscale systems

• DOI: 10.1016/j.applthermaleng.2021.117225
• 发表时间: 2021-07-03
• 期刊: APPLIED THERMAL ENGINEERING
• 影响因子: 6.4
• 作者: Shockner, Tomer;Chowdhury, Tanvir Ahmed;Ziskind, Gennady
• 通讯作者: Ziskind, Gennady

The Effect of the Stiffness of Soft Materials on Hemiwicking Performance

软材料的刚度对半吸湿性能的影响

• DOI: 10.1109/itherm45881.2020.9190180
• 发表时间: 2020
• 期刊: 2020 19th IEEE Intersociety Conference on Thermal and Thermomechanical Phenomena in Electronic Systems (ITherm
• 作者: Germain, Thomas;Putnam, Shawn A.
• 通讯作者: Putnam, Shawn A.

Hotspot Cooling Performance of Two-Phase Confined Jet Impingement Cooling at the Stagnation

两相受限射流冲击停滞时的热点冷却性能

• 发表时间: 2022
• 期刊: 2022 21st IEEE Intersociety Conference on Thermal and Thermomechanical Phenomena in Electronic Systems (iTherm
• 作者: Chowdhury, Tanvir A.;Putnam, Shawn A.
• 通讯作者: Putnam, Shawn A.

A simple analytic model for predicting the wicking velocity in micropillar arrays

• DOI: 10.1038/s41598-019-56361-7
• 发表时间: 2019-12-27
• 期刊: SCIENTIFIC REPORTS
• 影响因子: 4.6
• 作者: Krishnan, Siva Rama;Bal, John;Putnam, Shawn A.
• 通讯作者: Putnam, Shawn A.

Hotspot Cooling Performance of a Submerged Water Jet via Infrared Thermometry

• DOI: 10.1109/itherm45881.2020.9190595
• 发表时间: 2020-07
• 期刊: 2020 19th IEEE Intersociety Conference on Thermal and Thermomechanical Phenomena in Electronic Systems (ITherm)
• 作者: T. Chowdhury;C. Brewer;S. Putnam