主题：利用动态滑移边界进行湍流边界层控制和减阻
主讲：王聪 博士 (美国爱荷华大学机械工程系)
时间：2023年12月6日(周三)下午13:30
地点：上海市静安区延长路149号力学所200室
主持：卢东强
【摘要】The wall-bounded turbulent flows over the surfaces of airplanes or oil tankers produce a tremendous amount of drag force, thereby substantially undermining the energy efficiency of transportation systems. Consequently, a basic understanding of and effective control over wall-bounded turbulent flow have been long-standing pursuits for both scientists and engineers. Although many promising drag reduction techniques have been developed (e.g., the super-hydrophobic surface method), sustainable drag reduction remains a fundamental challenge.
In this presentation, I will introduce a novel method that employs an array of wall-attached oscillating free-slip air-film surfaces, capable of achieving a substantial drag reduction effect (more than 40%). The physics of oscillating free-slip surfaces interacting with quiescent water, laminar boundary layers, and turbulent boundary layers will be discussed, revealing the mechanism of drag reduction. These oscillating free-slip surfaces generate long-lasting coherent streamwise vortices, lifting the high-shear motions away from the wall boundary. An energy exchange analysis demonstrates that the turbulent flow near the wall partially re-laminarizes through a reversed energy cascade process. These fundamental discoveries hold significant value for the development of an optimal drag reduction technique.
【个人简介】王聪 博士2013年本科毕业于新加坡国立大学工程科学系，同年赴美国加州理工学院航空系攻读研究生课程，于2014和2019年在加州理工学院获得航空学硕士、博士。2019至2023年在加州理工学院航空航天系任博士后、研究科学家。2023年加盟爱荷华大学机械工程系担任Assistant Professor。王聪博士主要从事与湍流、多相流有关的工程问题研究（例如船舶水动力学），并致力于开发先进的复杂流体测量方法（例如三维PIV）。曾获2009新加坡教育部奖学金、加州理工学院2013 GALCIT fellowship、2015 Stanback fellowship、2018 Ernest Sechler纪念奖和2019 Donald Coles 奖（最佳实验设计奖）等奖励和荣誉。
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