A discrete-vortex analysis of flow about stationary and transversely oscillating circular cylinders

Abstract

A comprehensive numerical model has been developed to investigate the characteristics of flow about a circular cylinder undergoing synchronized transverse oscillations. The model is based on the rediscretization of the shear layers, wake-boundary-layer interaction, and the dissipation of vorticity. The forces acting on the cylinder, rate of vorticity flux, Strouhal number, cylinder response, oscillations of the stagnation and separation points, longitudinal and transverse spacing of the vortices, and the base pressure have been calculated and shown to be in conformity with those obtained experimentally. The model has been used to predict the characteristics of hydroelastic oscillations of a cylinder in the range of synchronization. The numerical experiments shed considerable light on the interaction between the fluid motion in the wake and the dynamics of the body. An extensive sensitivity analysis has been carried out to determine the stability of all the parameters and hence the stability of the numerical model itself. (Author)