Dynamics of secondary vortices in turbulent channel flow

Secondary vortical structures in a straight channel of rectangular cross-section are studied in details experimentally. Special attention is devoted to theirs dynamics. The stereo time-resolved PIV method is used to acquire time series of the 3-component vector fields in plane perpendicular to the mean flow. Dynamics of the vortical structures in the vector fields is studied using Proper Orthogonal Decomposition method. The dynamical modes are shown.