Numerical Simulation of the Influence of Rounded Corners on Flow Around a Square Column

The flow around a two-dimensional smooth square column with rounded corners at subcritical Reynolds number is simulated using the finite-volume open-source software OpenFOAM. The effects of turbulence are accounted for by using a two-equation turbulence closure specifically adapted to account for the interactions between periodic vortex shedding and random turbulence. The computational approach is first validated against data for the flow past a sharp square column. The purpose of this paper is to assess the model’s applicability to the more challenging case where the column corners are rounded. Of special interest is the prediction of the pressure distribution and the unsteady force coefficients induced by periodic vortex shedding from this geometry. The computed results show that the effects of rounded corners are to progressively reduce the drag and lift coefficients, while increasing the base pressure levels relative to the case of sharp corners.