A General Theory for the Effect of Large-Scale Freestream Turbulence on Surface Heat Transfer

大规模自由流湍流对表面传热影响的一般理论

• 批准号: 0423013
• 负责人: Thomas Diller
• 金额: --
• 依托单位: Virginia Polytechnic Institute and State University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2004
• 资助国家: 美国
• 起止时间: 2004-10-01 至 2009-09-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0423013&HistoricalAwards=false
• 关键词: General; Theory; Effect; Large; Scale

Abstract: A new approach is proposed for studying the effect of fluid motion on heat transfer. Special attention is given to the details of the time-dependent structure of large-scale turbulence and the associated interactions with surfaces. The results will be important in many industrial engineering situations, for example, combustors, electronic cooling devices, gas turbine engines, building structures, and heat exchangers. The innovative approach combines time-resolved visualization of the fluid flow with simultaneous measurements of the surface heat flux. A new type of microscale sensor array will be developed for the heat flux measurements using thin-film fabrication processes. The experiments will be used to validate a simple physical model based on the coherent structure of the flow and its interaction with the surface. So far, the model has successfully predicted the overall increase in the heat transfer due to large-scale freestream turbulence in several different geometries for both low and high speed flows. Although the approach is novel and risky, if proven successful, the impact of the results will be far reaching and will broadly extend our understanding of the effects of turbulence on heat transfer. The broader impacts of the proposed research include the diverse group of the graduate students who will be trained in state-of-the-art experimental techniques, the education of a large number of undergraduate mechanical engineering students (over 200 per year will be impacted), and the interactions with other engineers and scientists. The microscale sensor arrays developed will be shared with industry and labs around the world. If successful, the leap in understanding of turbulent heat transfer will be shared with researchers and practitioners of heat transfer in many fields of engineering from the mega scales of atmospheric turbulence to the micro scales of electronic cooling. The benefits to society will be derived from the improved utilization and control of energy in many products and processes. This award has been funded by the Thermal Transport and Thermal Processing Program of the Chemical and Transport Systems Division.

摘要：提出了一种研究流体运动对传热影响的新方法。特别关注大规模湍流的时间相关结构的细节以及与表面的相关相互作用。研究结果对于许多工业工程情况非常重要，例如燃烧器、电子冷却装置、燃气涡轮发动机、建筑结构和热交换器。这种创新方法将流体流动的时间分辨可视化与表面热通量的同步测量相结合。将开发一种新型微型传感器阵列，用于使用薄膜制造工艺进行热通量测量。这些实验将用于验证基于流动的相干结构及其与表面相互作用的简单物理模型。到目前为止，该模型已成功预测了由于低速和高速流动的几种不同几何形状中的大规模自由流湍流而导致的传热总体增加。尽管该方法新颖且存在风险，但如果被证明成功，其结果的影响将是深远的，并将广泛扩展我们对湍流对传热影响的理解。 拟议研究的更广泛影响包括将接受最先进实验技术培训的不同研究生群体、大量机械工程本科生的教育（每年超过 200 名学生将受到影响） ，以及与其他工程师和科学家的互动。开发的微型传感器阵列将与世界各地的工业界和实验室共享。如果成功，从大尺度的大气湍流到微观尺度的电子冷却，许多工程领域的传热研究人员和实践者将分享对湍流传热理解的飞跃。许多产品和工艺中能源利用和控制的改善将给社会带来好处。该奖项由化学和运输系统部门的热运输和热处理项目资助。