U.S.-Netherlands Cooperative Research on the Structure of a Turbulent Boundary Layer with Suction

美国-荷兰关于吸力湍流边界层结构的合作研究

• 批准号: 9600213
• 负责人: Minami Yoda
• 金额: $ 1.02万
• 依托单位: Georgia Tech Research Corporation
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 1996
• 资助国家: 美国
• 起止时间: 1996-08-01 至 1998-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9600213&HistoricalAwards=false
• 关键词: U.S.; Netherlands; Cooperative; Research; Structure

This award supports Assistant Professor Minami Yoda of Georgia Institute of Technology to collaborate in mechanical engineering research with Professor F.T.M. Nieuwstadt of the Laboratory of Aeroand Hydrodynamics of the Delft University of Technology, The Netherlands. Using particle imaging velocimetry, they will carry out a study of a turbulent boundary layer with and without suction in the vicinity of a few holes of a diameter of ten percent of the local boundary layer thickness. The Dutch laboratory has excellent experimental facilities for this research, and the experience with their set-up to be gained by the US PI will provide the basis for deciding whether and how to establish similar facilities at Georgia Tech. The two laboratories bring to the research effort complementary expertise in both hydrodynamic systems and specialized instrumentation: Delft in bounded flows and the application of particle imaging velocimetry and Georgia Tech in free shear flow control and laser-induced fluorescence. Turbulence increases drag (and operating cost) on moving surfaces such as airplane wings. Suction is known to re- laminarize and delay the separation of turbulent boundary layers, but too much suction can actually increase the separation. Suction through large holes or slots has been widely studied; smaller holes work better, but the cost of implementing has been found not to be worth the savings in drag. While new technology now permits economical production of minutely perforated surfaces, relatively little is known about the effect of suction on such small holes on the boundary layer structure. This work will help to clarify how such suction affects the coherent structures in the boundary layers, and increase understanding of `aerodynamic roughness`, where strong suction levels actually cause separation.

该奖项支持佐治亚理工学院的 Minami Yoda 助理教授与 F.T.M. 教授在机械工程研究方面进行合作。荷兰代尔夫特理工大学空气和流体动力学实验室的 Nieuwstadt。 他们将利用粒子成像测速技术，对直径为局部边界层厚度百分之十的几个孔附近有吸力和无吸力的湍流边界层进行研究。 荷兰实验室拥有用于这项研究的优良实验设施，美国PI将获得的设置经验将为决定是否以及如何在佐治亚理工学院建立类似设施提供基础。 这两个实验室为研究工作带来了流体动力学系统和专用仪器方面的互补专业知识：代尔夫特在有界流和粒子成像测速应用方面以及佐治亚理工学院在自由剪切流控制和激光诱导荧光方面。 湍流会增加飞机机翼等运动表面的阻力（和运行成本）。 众所周知，吸力可以重新层流并延迟湍流边界层的分离，但过多的吸力实际上会增加分离。 通过大孔或槽进行吸力已被广泛研究；孔越小效果越好，但人们发现实施成本不值得节省阻力。 虽然新技术现在可以经济地生产微小穿孔表面，但人们对吸力对边界层结构上此类小孔的影响知之甚少。 这项工作将有助于阐明这种吸力如何影响边界层中的相干结构，并增加对“空气动力学粗糙度”的理解，其中强吸力水平实际上会导致分离。