DISCRETE VORTEX MODEL OF FLOW OVER A SQUARE CYLINDER

The discrete vortex method (DVM) is used to numerically study the velo city field in the near wake of a 2-D cylinder of square cross-section. Vortex panels are used to model the cylinder surface, at which a no-p enetration boundary condition was imposed. The DVM uses a series of in dividual vortex elements to model the separated shear layers of the cy linder. The discrete-vortex elements interact to form clusters in the wake region, which represent the larger vortical structures present in such flows. By careful choice of numerical parameters, good agreement is obtained with experimental measurements for the mean and fluctuati ng velocity fields in the near-wake region. The method is especially e ffective in modelling the unsteady, quasi-periodic motions associated with the large-scale vortex structures in the wake.