Suppression of vortex shedding on a bluff body

Previous experimental observations suggest that a moving ground can be numerically simulated avoiding vorticity generation on it. In this research line the current paper presents a two-dimensional Lagrangian Vortex Method, which is able to analyze the vortex shedding suppression on a circular cylinder near a moving ground in a high Reynolds number flow of Re=1.0×105. The main purpose is to utilize numerical results to construct the instantaneous velocity and pressure fields for this kind of unsteady viscous flow. The analyses demonstrate that the physical mechanisms involved are associated with an additional circulation caused by the fluid viscosity and with the Venturi effect. Both of these effects are responsible for the increase in lift force as well as for the decrease in drag force acting on body surface. •Blockage effect: the mechanism responsible for the big and small peaks on the drag curve.•Viscosity effect: it causes a change in the stagnation point, which arouses an increase in lift force.•Venturi effect: it draws the counter-clockwise vortex structure downstream, which inhibits the boundary layer formation on the ground.