Leading-edge receptivity of boundary layer to three-dimensional free-stream turbulence  

作　　者：Luyu SHEN Changgen LU Xiaoqing ZHU 

机构地区：[1]School of Marine Sciences, Nanjing University of Information Science & Technology

出　　处：《Applied Mathematics and Mechanics(English Edition)》2019年第6期851-860,共10页应用数学和力学（英文版）

基　　金：supported by the National Natural Science Foundation of China(Nos.11472139 and11802143);the Natural Science Foundation of Jiangsu Province of China(No.BK20180781)

摘　　要：The laminar-turbulent transition has always been a hot topic of fluid mechanics. Receptivity is the initial stage and plays a crucial role in the entire transition process. The previous studies of receptivity focus on external disturbances such as sound waves and vortices in the free stream, whereas those on the leading-edge receptivity to the three-dimensional free-stream turbulence (FST), which is more general in the nature, are rarely reported. In consideration of this, this work is devoted to investigating the receptivity process of three-dimensional Tollmien-Schlichting (T-S) wave packets excited by the three-dimensional FST in a flat-plate boundary layer numerically. The relations between the leading-edge receptivity and the turbulence intensity are established, and the influence of the FST directions on the propagation directions and group velocities of the excited T-S wave packets is studied. Moreover, the leading-edge receptivity to the anisotropic FST is also studied. This parametric investigation can contribute to the prediction of laminar-turbulent transition.The laminar-turbulent transition has always been a hot topic of fluid mechanics. Receptivity is the initial stage and plays a crucial role in the entire transition process. The previous studies of receptivity focus on external disturbances such as sound waves and vortices in the free stream, whereas those on the leading-edge receptivity to the three-dimensional free-stream turbulence(FST), which is more general in the nature,are rarely reported. In consideration of this, this work is devoted to investigating the receptivity process of three-dimensional Tollmien-Schlichting(T-S) wave packets excited by the three-dimensional FST in a flat-plate boundary layer numerically. The relations between the leading-edge receptivity and the turbulence intensity are established, and the influence of the FST directions on the propagation directions and group velocities of the excited T-S wave packets is studied. Moreover, the leading-edge receptivity to the anisotropic FST is also studied. This parametric investigation can contribute to the prediction of laminar-turbulent transition.

关 键 词：LEADING-EDGE RECEPTIVITY free-stream turbulence (FST) boundary layer THREE-DIMENSIONAL Tollmien-Schlichting (T-S) wave 

分 类 号：O357[理学—流体力学]