不同入射角下圆柱涡激振动的数值研究

The effects of four different inflow angles (a) on the vortex-induced vibration responses of a two-degree- of-freedom cylinder were studied using the two-dimensional unsteady Reynolds -averaged N-S equation and the shear stress transport k - co model，combined with the fourth-order Runge-Kutta method. The effects of different incoming flow angle on the amplitude of vortex-induced vibration, structural vibration frequency, locking interval, vortex shedding mode, Strouhal number, hydrodynamic coefficient and energy capture efficiency were analysed and the results were compared. The numerical results show that the change of the incoming flow angle will make the vortex-induced vibration responses of the cylinder produce multi-frequency characteristics, and with the increase of the incoming flow angle, the amplitude in the y direction gradually decreases and the amplitude in the x direction gradually increases. Different incoming flow angles all have obvious locking phenomenon，but the width of locking interval has no obvious change with the change of incoming flow angle. With the increase of inflow angle，the root mean square of the force coefficient in y direction and the mean value of the force coefficient in x direction both tend to decrease.