Interaction of a vortex ring with a cutting thin plate

Abstract

An experimental study was made on symmetrically cut of a vortex ring by a finite length thin plate. The interaction was studied to evaluate flow features using volumetric three component flow velocimetry (V3V) system. Vortex rings were generated using a piston-cylinder mechanism at jet Reynolds numbers of 1500 and 2000 with piston stroke length-to-diameter ratios of 2 and 3. Experiments were made for the plate thickness of 0.86mm, plate length to diameter ratio of 0.13 and 0.536, and with a cut of vortex ring on the centerline and below the centerline. The interaction of vortex ring with plate showed strong dependence on cutting depth. For the case of cutting below the centerline of the vortex ring showed formation of the three vortex rings. One moved in the same line as the primary vortex ring and other two moved perpendicular to the plate (one in each side with respect to the centerline of the primary vortex ring). On the other hand, for the case of the vortex ring cut up to the centerline axis showed generation of a centerline vortex ring with a vortical structure circulating around the vortex ring loop.