基于有限差分法刚性圆柱体涡激振动响应特性数值研究

Numerical study based on a wake oscillator model is conducted to determine response performance of vortex-induced vibration (VIV) on a rigid cylinder. A coupled model of structural oscillator of a rigid cylinder and wake oscillator is established, and then the model is discretized and solved based on a standard central finite difference method of the second order. VIV response characteristics including dimensionless displacement, dimensionless lift, and frequency ratio and lock-in region varied with mass ratios and damping ratios are compared. It can be found that the numerical method simulates response performances of vortex-induced vibration on a rigid cylinder very well. As dimensionless mass ratio increases, onset of lock-in region occurs later, lock-out point occurs earlier, and so the lock-in region becomes smaller.