Coherent structures in wall turbulence and mechanism for drag reduction control  

作　　者：XU ChunXiao DENG BingQing HUANG WeiXi CUI GuiXiang 

机构地区：[1]Department of Engineering Mechanics,Tsinghua University

出　　处：《Science China(Physics,Mechanics & Astronomy)》2013年第6期1053-1061,共9页中国科学：物理学、力学、天文学（英文版）

基　　金：Tsupported by the National Natural Science Foundation of China (Grant Nos. 10925210 and 11132005)

摘　　要：Herein is introduced the mechanism for active control influencing the generation of the near-wall streamwise vortices,which are closely related to the production of high skin friction in wall-bounded turbulent flows.A new opposition control scheme with adjusting control amplitude is proposed and evaluated in turbulent channel flow by direct numerical simulations.The maximum drag reduction rate can be greatly enhanced by the strengthened control.Finally the effectiveness of the control to the coherent structures at high Reynolds numbers is investigated by using a linear transient growth model.Herein is introduced the mechanism for active control influencing the generation of the near-wall streamwise vortices,which are closely related to the production of high skin friction in wall-bounded turbulent flows.A new opposition control scheme with adjusting control amplitude is proposed and evaluated in turbulent channel flow by direct numerical simulations.The maximum drag reduction rate can be greatly enhanced by the strengthened control.Finally the effectiveness of the control to the coherent structures at high Reynolds numbers is investigated by using a linear transient growth model.

关 键 词：wall turbulence coherent structure drag reduction active control 

分 类 号：O357.5[理学—流体力学] X169[理学—力学]