The aim of present study is to control the unsteady flow structure downstream of a circular cylinder by use of attached permeable plates. Particle image velocimetry (PIV) technique and dye visualization experiments were performed in deep water and the flow characteristics were evaluated by means of time-averaged streamlines, Reynolds Shear Stress and Turbulent Kinetic Energy concentrations. The...

Periodic vortex streets, often considered as a model for the organized structures observed in the wake of two-dimensional (2D) bluff bodies, are revisited. After the generation of the shear layers the formation of the vortices is mainly an inviscid process. An intrinsic scaling for the formation of vortex streets is found based on the invariants of motion for 2D inviscid flows; namely the kinet...

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The present article represents part of the PhD. dissertation by C. Josserand1. We discuss the nucleation of quantized vortices in the nonlinear Schrödinger equation (NLS) for a flow around a disk in two spatial dimensions. It appears that the vortices are nucleated when the flow becomes locally (at the edge of the disk) supersonic. A detailed study of the phase equation for the complex field ψ ...

Abstract A parked wind turbine can be subjected to large yaw angles, which causes vortex shedding. Under some particular inflow conditions, the interaction between shed vorticity and blade structure could lead Vortex-Induced Vibrations (VIV). VIV are an instability where response grows until it reaches a limit cycle oscillation. In this paper, we will focus on last part of response. We see that...

For flow-induced vibration of a rounded-square cylinder under the effect proximity interference by stationary splitter plate downstream, numerical study is presented for various corner-radius R(0.1−0.5), reduced velocity U*(2−12.5), cylinder-plate gap G*(0.3,2.0), Reynolds number Re = 100, mass ratio M*=1, damping coefficient ζ=0.005, plate-length L*=1, and plate-thickness t*=0.05. R, vortex-in...

Detached Eddy Simulation on a 13 M grid is conducted for a KVLCC2 tanker hull form at drift angle 301. The objective is to identify and analyze the vortical structures, instabilities, and turbulent structures with analogy to the vortex breakdown and helical instability analysis for delta wing at large angles of attack. One shear layer, one Karman-like vortex shedding, and three helical mode ins...