Effect of boundary conditions and domain size on the turbulent flow characteristics over a circular cylinder

Abstract

Numerical investigation of the effects of boundary conditions and computational domain size on simulations of a circular cylinder in three-dimensional (3-D) turbulent flow at Re=3900 has been conducted using a direct-forcing immersed boundary (DFIB) method. The turbulent flow scales were simulated using the Smagorinsky model. Two computational domain sizes and three different sets of boundary conditions were investigated. The results of all the cases were compared against published literature. The study proved the capability of the selected DFIB method for investigating fluid-structure interactions in turbulent flow. It also found that the increase in the size of the computational domain improved the accuracy of the results, especially in the far wake region. Interestingly, switching the lateral boundaries between periodic and symmetry conditions enabled the numerical simulation to approach the two different experimental results.