Numerical simulations of a wind-induced vibrating square cylinder within turbulent boundary layer

The wind-induced vibration of a square cylinder is simulated by solving Navier–Stokes equations. The width of the square cylinder is B and the height H is set as 4B. Reynolds number based on B and the velocity at the top UH is 28,500. The vibration mode of the cylinder is set as a rocking motion in crosswind direction. The turbulent boundary layer flows are reproduced at the inflow boundary in accordance with the corresponding wind–tunnel experiments. First the effects of inflow turbulence to the aerodynamic forces acting on the cylinder at rest are shown. Then vibration responses are presented by taking two different approaches. One is the spectrum modal analysis based on the time-depending wind forces acting on the cylinder at rest and the other is the aeroelastic computations. In the latter case, the grids for flow computations are moved and transformed at each time step depending on the cylinderʹs motion. Computed responses are compared with the wind–tunnel experiments. The places where the motion-induced aerodynamic forces act along its axis direction and the effect of reduced velocity to those places are also discussed.