Incompressible flow past a circular cylinder: dependence of the computed flow field on the location of the lateral boundaries

Abstract

The influence of the location of the lateral boundaries on 2D computation of unsteady incompressible flow past a circular cylinder is investigated. The case of Reynolds number 100 is used as a benchmark, and several quantities characterizing the unsteady flow are obtained for a range of lateral boundary locations. The computations are performed with two distinct finite element formulations - space-time velocity-pressure formulation and velocity-pressure-stress formulation. We conclude that the distance between the cylinder and the lateral boundaries can have a significant effect on the Strouhal number and other flow quantities. The minimum distance at which this influence vanishes has been found to be larger than what is commonly assumed.