摘要
通过拟谱方法对展向空间振荡电磁力控制槽道湍流问题进行研究.结果表明,选择合适的电磁力参数,展向空间振荡电磁力可影响涡结构生成,进而控制壁湍流.控制后的壁湍流流场存在以准流向涡和条带周期分布为主要特征的拟序结构,壁面阻力减小.如果将控制过程视作诱导流场对壁湍流固有流场的调制,研究发现,当壁湍流被有效控制时,流场的主要特征,如流向涡的几何形态,涡量方向及沿轴线的大小变化,以及涡的生成和消亡等都与诱导流场直接相关,从而也与电磁力的分布直接相关.基于此,文章阐述了展向电磁力控制壁湍流的内在机制.
Turbulent channel flow control by using a spanwise oscillating Lorentz force with steady distributions has been investigated numerically via the pseudo-spectral method. The turbulent control and the drag reduction can be achieved by spanwise oscillating Lorentz forces with proper control parameters. The vortex generation is impacted in the controlled turbulent channel flow, and that only periodically well-organized streamwise vortexes are observed in the near-wall region of the turbulent channel flow. If the turbulent control is regarded as a process in which the turbulence flow is modulated by the induced flow, it has been shown that the induced flow dominants the modulated flow field when the turbulent flow is effectively controlled by the Lorentz force. Therefore, basic features of streamwise vortices in the controlled flow, such as configurations, distributions and its formations and annihilations, are related with the induced flow field and the Lorentz force distributions closely, based on which the mechanism of the turbulent control is elucidated finally.
出处
《中国科学：物理学、力学、天文学》
CSCD
北大核心
2015年第9期14-24,共11页
Scientia Sinica Physica,Mechanica & Astronomica
基金
国家自然科学基金资助项目(批准号:11172140
11372356)
关键词
槽道湍流
拟谱方法
壁面减阻
电磁力
turbulent channel flow, pseudo-spectral method, drag reduction, Lorentz force
