Numerical computation of the flow around two square cylinders arranged side-by-side

The numerical method is used to calculate the flow around two square cylind ers arranged side-by-side and the mean and fluctuating aerodynamic forces, and Strouhal numbers and power spectrum of lift force and drag force are ob tained. An improved MAC method proposed by Chen Suqin et al.,which uses thr ee order upwind scheme to discretize the convection term and uses multigrid method to solve the Poisson equation for pressure is applied to simulate t he flow around two square cylinders arranged side-by-side. Results show tha t the interference characteristic of two square cylinders arranged side-by- side is completely different with the different spacing ratio. When the spa cing ratio is smaller than a certain critical value, the gap flow between t wo cylinders is biased to one side in a stable or unstable manner.