Vortex wake and energy transitions of an oscillating cylinder at low Reynolds number

Abstract

To better understand vortex-induced vibration at low Reynolds number, a two-dimensional numerical study of the forced oscillation of a cylinder in cross-flow was undertaken. The Karman vortex shedding mode (2S) of the forced oscillation of a cylinder in cross-flow incorporated a gradual change from positive to negative energy transfer with increasing amplitude of motion. As amplitude was increased, the 2S shedding mode evolved into an asymmetric mode of shedding in which a pair and a single vortex (P+S) were shed each motion cycle. Energy contours were established in the region of primary lock-in and the boundary of zero energy transfer was defined. The observed P+S mode only occurred in the region of negative energy transfer.