Experimental study on orbital response and flow behavior behind a freely suspended cylinder

This paper presents an experimental study of the trajectory and flow behavior behind a freely suspended circular cylinder in a uniform flow. The cylinder was suspended from a platform and the assembly was free to move freely in the horizontal plane. The trajectories of the cylinder and wake flow fields were captured using a camera and the Particle Image Velocimetry (PIV) technique, respectively. The effects of free stream velocity on the orbital response and vortex wake mode of the cylinder were examined. Depending on the free stream velocity, different trajectories of the suspended cylinder were observed such that: (i) with oscillations of negligible amplitude, similar to a stationary cylinder; (ii) oscillations like an elastically mounted cylinder; (iii) intermittent oscillations and horizontal translation; (iv) traversing downstream with large transverse oscillations. Finally it was observed that the vortex wake mode was sensitive to the location of the cylinder, and changed as the cylinder traveled downstream.