Wall Turbulence Control and Skin-Friction Drag Reduction with Novel Surface Microstructures

利用新型表面微观结构控制壁面湍流并减少表面摩擦阻力

• 批准号: 2039433
• 负责人: Taiho Yeom
• 金额: $ 35.25万
• 依托单位: University of Mississippi
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2021
• 资助国家: 美国
• 起止时间: 2021-03-01 至 2025-02-28
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2039433&HistoricalAwards=false
• 关键词: Wall; Turbulence; Control; Skin; Friction

Skin-friction drag is responsible for energy loss for ships, aircraft, and the trucking industry. This project explores innovative methods of reducing skin-friction drag using computations and experiments. One of the promising methods for reducing skin-friction drag is to dampen wall turbulence passively using surface microstructures. While a substantial amount of effort has been made to advance wall techniques, the process is not yet completely understood. The primary aim of this project is to provide a fundamental understanding of the underlying physics of these novel surface microstructures and show that they can provide systematic control of wall turbulence to minimize skin-friction drag. The project outcomes will be disseminated to broader communities through many educational and outreach activities, such as undergraduate research programs, scientific publications, conference presentations, and summer science camps to K-12 students and teachers.A micro airfoil structure, which is a newly proposed surface microstructure, is expected to achieve unique turbulence control capabilities due to its well-defined 3D geometry. The main objectives of the project are: (i) to demonstrate the turbulence control capability using the micro airfoil structure, (ii) to identify the connections between the control inputs created by the micro airfoil structure and the responses of skin-friction drag, (iii) to understand the fundamental mechanisms of the turbulence control and skin-friction drag reduction by the micro airfoil structure, and (iv) to recommend the optimum configurations of the single and arrays of micro airfoil structure for the maximum reduction of skin-friction drag. Direct numerical simulation and large eddy simulation will be used to compute fundamental flows, and particle image velocimetry will be used to measure velocities in the turbulent boundary layer. The fundamental knowledge obtained through this project will provide insight to answer the long-lasting questions about the dynamics of wall-bounded turbulent flows. The unique turbulence control techniques achieved by the micro airfoil structure will provide guidance to other research areas in aerospace, mechanical, chemical, and ocean engineering where turbulence control may lead to drag reduction. This project is jointly funded by Fluid Dynamics and the Established Program to Stimulate Competitive Research (EPSCoR) programs.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.

皮肤摩擦阻力负责船舶，飞机和卡车行业的能源损失。该项目探讨了使用计算和实验减少皮肤摩擦阻力的创新方法。减少皮肤摩擦阻力的有前途的方法之一是使用表面微观结构对壁湍流抑制。尽管已经付出了巨大的努力来推进墙壁​​技术，但该过程尚未完全理解。该项目的主要目的是提供对这些新型表面微观结构的潜在物理学的基本理解，并表明它们可以对壁湍流进行系统的控制，以最大程度地减少皮肤摩擦的阻力。该项目的成果将通过许多教育和外展活动将其传播到更广泛的社区，例如本科研究计划，科学出版物，会议演讲以及K-12学生和老师的夏季科学训练营。由于其良好的构​​成良好的3D GEOMENTRY，预计新建议的表面微观结构是一种新建议的表面微观结构，该结构将获得独特的湍流控制能力。 The main objectives of the project are: (i) to demonstrate the turbulence control capability using the micro airfoil structure, (ii) to identify the connections between the control inputs created by the micro airfoil structure and the responses of skin-friction drag, (iii) to understand the fundamental mechanisms of the turbulence control and skin-friction drag reduction by the micro airfoil structure, and (iv) to recommend the optimum configurations of the single and微型机翼结构的阵列，以最大程度地减少皮肤摩擦阻力。直接的数值模拟和大型涡流模拟将用于计算基本流，并且将使用粒子图像速度测定法来测量湍流边界层中的速度。通过该项目获得的基本知识将提供洞察力，以回答有关壁挂式湍流动态的长期问题。微型机翼结构实现的独特湍流控制技术将为航空航天，机械，化学和海洋工程的其他研究领域提供指导，在该领域，湍流控制可能会导致减少阻力。该项目由流体动力和启发竞争研究计划（EPSCOR）计划共同资助。该奖项反映了NSF的法定任务，并被认为是值得通过基金会的知识分子优点和更广泛的影响评估的评估来支持的。