PIV Study of the Vortex Wake behind a Translationally Oscillating Cylinder in a Quiescent Fluid

The near wake produced by a circular cylinder oscillating translationally in a quiescent fluid or, alternatively, by oscillatory flow past a stationary cylinder at low Keulegan-Carpenter (KC) and Stokes (b) numbers has been investigated using Particle Image Velocimetry. All but one of the two- and three-dimensional regimes of the Tatsuno & Bearman [11] map were investigated. The findings are successfully compared with previous experimental observations and numerical simulations. Twodimensional Particle Image Velocimetry results of regime B show how the symmetrical pattern of vortices around the cylinder becomes three-dimensional. Additionally, the instantaneous results of regime E confirm that there is an intermittent change in the direction of the V-shaped vortices around the cylinder