Coherent structures over riblets in turbulent boundary layer studied by combining time-resolved particle image velocimetry (TRPIV), proper orthogonal decomposition (POD), and finite-time Lyapunov exponent (FTLE)
Li Shan1, Jiang Nan1, †, Yang Shaoqiong1, ‡, Huang Yongxiang2, Wu Yanhua3
       

(color online) Wall-normal distribution of the inclination angles of LCSs.