HEAT TRANSFER IN FLUIDS AT NEAR-CRITICAL PRESSURES: EXPERIMENTS AND MATHEMATICAL MODELING

近临界压力下流体的传热：实验和数学建模

• 批准号: 0553571
• 负责人: Gopinath Warrier
• 金额: --
• 依托单位: University of California-Los Angeles
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2006
• 资助国家: 美国
• 起止时间: 2006-09-15 至 2010-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0553571&HistoricalAwards=false
• 关键词: HEAT; TRANSFER; FLUIDS; NEAR; CRITICAL

ABSTRACTNational Science FoundationProposal Number CTS-0553571Principal Investigator Warrier, GopinathAffiliation University of California-Los AngelesProposal Title Heat Transfer in Fluids at Near Critical Pressures: Experiments and Mathematical ModelingHigh pressure fluids are increasingly being promoted as heat transfer media in a number of thermal and chemical processes such as cryogenic cooling systems, thermosyphons, and large Supercritical Water-Cooled Reactors (SCWR). However, due to the rapid change in fluid properties close to the critical point, the experimental results have yielded both heat transfer enhancement and deterioration. The results for these contradictory results are not clearly understood. In this fundamental study, the heat transfer mechanisms involved during natural convection and boiling from microscale heater elements at near-critical pressures will be investigated. Both Schlieren photography and Particle Image Velocimetry will be employed. Models/correlations suitable for design purposes will be developed based on the experimental data. In addition to the experiments, numerical simulations using Direct Numerical Simulation (DNS) will also be performed. The temperature and velocity data obtained in the experiments will be used to validate the numerical simulations. Intellectual Merit: The proposed study will greatly advance the basic understanding of heat transfer in fluids at pressures near the critical pressure. The knowledge gained will provide researchers, in academia and industry, with a better understanding of the process. Potential innovative applications of this knowledge include miniature thermosyphons and heat pipes, cryogenic cooling systems, and in a broader sense SCWR thermal-hydraulics during shut down modes and reactor transients.Broader Impact: The project will support at least two undergraduate students from underrepresented groups to come and work in the laboratory during each summer. This will give the students a chance to gain valuable hands on experience and stimulate their interest in the field of thermal science and engineering. Two Ph.D. students will also be supported as part of this project. The research accomplished will be presented at conferences and published in archival journals for general dissemination by the technical community.

摘要国家科学基金会提案编号 CTS-0553571 首席研究员 Warrier, Gopinath 附属加州大学洛杉矶分校提案标题 近临界压力下流体传热：实验和数学建模高压流体越来越多地被推广为许多热和化学过程中的传热介质，例如低温冷却系统、热虹吸管和大型超临界系统 水冷反应堆（SCWR）。然而，由于接近临界点时流体性质的快速变化，实验结果既产生了传热强化，也产生了传热恶化。这些相互矛盾的结果的结果尚不清楚。 在这项基础研究中，将研究在近临界压力下微型加热器元件自然对流和沸腾过程中涉及的传热机制。 将采用纹影摄影和粒子图像测速技术。将根据实验数据开发适合设计目的的模型/相关性。除了实验之外，还将使用直接数值模拟（DNS）进行数值模拟。实验中获得的温度和速度数据将用于验证数值模拟。 智力价值：拟议的研究将极大地增进对接近临界压力的流体传热的基本理解。获得的知识将使学术界和工业界的研究人员更好地理解这一过程。这些知识的潜在创新应用包括微型热虹吸管和热管、低温冷却系统，以及更广泛意义上的超临界水堆在关闭模式和反应堆瞬变期间的热工水力。更广泛的影响：该项目将支持至少两名来自代表性不足群体的本科生在每年夏天到实验室工作。这将使学生有机会获得宝贵的实践经验并激发他们对热科学与工程领域的兴趣。两名博士作为该项目的一部分，学生也将得到支持。完成的研究将在会议上展示并在档案期刊上发表，以供技术界广泛传播。