Interaction of a streamwise vortex with a thin plate - A source of turbulent buffeting

The three-dimensional interaction of a streamwise vortex with a thin plate (simulated tail or fin) is investigated experimentally using high-image-density particle image velocimetry, which allows determination of the instantaneous streamline patterns and distributions of vorticity over entire planes of the flow. These representations of the flow reveal that the vortex-plate encounter generates a new type of vortex splitting, leading to two smaller-scale concentrations of streamwise vorticity. Their trajectories rapidly diverge from the plane of symmetry of the plate. Details of this encounter process are interpreted using instantaneous values of circulation, two-dimensional vorticity correlation functions, and length scales of the vorticity field