Cinema PIV and its application to impinging vortex systems

An integrated cinema PIV-pressure measurement system allows derailed insigh t into impinging vortex systems. It employs a high framing rate camera in c onjunction with a scanning-laser version of high-image-density particle ima ge velocimetry, thereby generating space-time representations of the flow. Simultaneously, instantaneous surface pressures are acquired. This approach allows the instantaneous velocity and vorticity field's to be related to t he induced loading. The instantaneous structure of vortex systems arising f rom an initially turbulent jet impinging upon an edge and an initially turb ulent sheer layer past a cavity are quantitatively characterized for the fi rst time. In addition, distinctive mechanisms of vortex-wedge and vortex-co rner interactions are related to the occurrence of peak values of instantan eous surface pressure.