NUMERICAL STUDY OF PRESSURE-FLUCTUATIONS ON A RECTANGULAR CYLINDER IN AERODYNAMIC OSCILLATION

We numerically simulate unsteady flow fields around a forced-oscillating rectangular cylinder. The higher-order finite difference computation of the two-dimensional incompressible Navier-Stokes equations is applied to the dynamic interaction between the vortex motions and the torsional oscillation of a rectangular cylinder. In order to clarify the physical mechanism of the aerodynamic damping forces and the self-excited forces, we investigate the pressure fluctuations acting on the side surface. According to the computational how visualization of the instantaneous vorticity, the vortices shed from the leading edge are controlled by the motion of a rectangular cylinder and the lock-on patterns of vortex shedding are clearly seen under the proper conditions.