Dynamics of the kinematic structure of a separated flow behind transversal ribs at transition to turbulence has been studied. Smoke visualization using a high-speed camera, hot-wire measurements of velocity and skin friction, and PIV-measurements of instantaneous vector fields of flow velocity and vorticity were carried out. The data on the features of origination and main regularities of evolution of large-scale vortices generated in the mixing layer starting from a certain Reynolds number was obtained. Statistical treatment of PIV-measurements revealed the effect of the rib shape on the distribution of an average longitudinal velocity component and the second moments of velocity fluctuations in the channel behind the ribs at different stages of transition to turbulence.
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