Prediction of unsteady flow around square and rectangular section cylinders using a discrete vortex method

Abstract

A discrete vortex method has been developed at the Department of Aerospace Engineering, University of Glasgow to predict unsteady, incompressible, separated flows around closed bodies. The basis of the method is the discretisation of the vorticity field, rather than the velocity field, into a series of vortex particles which are free to move in the flow. The grid free nature of the method allows analysis of a wide range of problems for both stationary and moving bodies. This report presents a brief description of the numerical implementation, and presents the results of an extensive validation of the method on bluff body flow fields. Results are presented for the mean force coefficients, surface pressure coefficients and Strouhal numbers on a square section cylinder at varying angle of incidence. Also presented are the mean force coefficients and Strouhal numbers on rectangular cylinders. The results from the vortex method show good agreement, both qualitative and quantitative, with results taken from various experimental data.