WAKE-BOUNDARY LAYER INTERACTIONS BEHIND A SQUARE CYLINDER FOR A REYNOLDS NUMBER IN PERIODIC VORTEX SHEDDING REGIME

摘要

Flow over a square cylinder in proximity to a wall for different gap-to-diameter ratios (G/D = 0 to 2, where G is the gap between the cylinder and flat plate and D is the side of the square cylinder) has been studied extensively for a Reynolds Number (Re = U_∞D/v, where v is the kinematic viscosity of the fluid and U_∞ is the free stream velocity) in the periodic vortex shedding regime. Ansys Fluent is used to solve two-dimensional (2-D), time dependent, incompressible Navier-Stokes equation by SIMPLE [1] algorithm implemented in finite volume method. Interesting flow features and changes in vortex dynamics can be seen by the present simulation, when the cylinder approaches very close to the plate. The boundary layer formed over the flat plate changes its characteristics for these low gap-ratios. Also the modification of the aerodynamic forces and the vortex shedding frequency are thoroughly described to understand the physics behind wake-boundary layer interaction at low Reynolds Number.