Cinema PIV and Its Application to Impinging Vortex Systems

Abstract

An integrated cinema PIV-pressure measurement system allows detailed insight into impinging vortex systems. It employs a high framing rate camera in conjunction with a scanning-laser version of high-image-density particle image velocimetry, thereby generating space-time representations of the flow. Simultaneously, instantaneous surface pressures are acquired. This approach allows the instantaneous velocity and vorticity fields to be related to the induced loading. The instantaneous structure of vortex systems arising from an initially turbulent jet impinging upon an edge and an initially turbulent shear layer past a cavity are quantitatively characterized for the first time. In addition, distinctive mechanisms of vortex-wedge and vortex-corner interactions are related to the occurrence of peak values of instantaneous surface pressure.