典型2维柱体涡激振动的数值模拟研究

Study on Vortex Induced Vibration for Typical Cylinders Using Numerical Method

摘要:

利用作者编制的基于松耦合方法的求解气动弹性问题的程序，对圆柱和方柱等典型2维柱体的涡激振动进行了数值模拟.计算结果表明：2维柱体的涡激振动存在2个锁定状态，即低折减风速条件下的流向锁定和高折减风速条件下的横向锁定；随着折减风速的增大，2维柱体的旋涡脱落模式从异向2S(2single)变化到同向2S；伴随着旋涡脱落模式的转变，气动力和位移之间的相位差出现0→π的剧烈变化，即相位转换现象；通过对相位转换现象进行分析，给出了涡激振动是限幅振动的机理解释.

Abstract:

By virtue of the code for the aeroelastic problems based on the loosely coupled method worked out by the authors,vortex induced vibration (VIV) for typical cylinders,including circular and square cylinders are simulated. Computational results show that there exist two lock in states for the VIV of the two dimensional cylinders:one is streamwise lock in at lower reduced velocity and the other is lateral lock in at higher reduced velocity.With the increase of the reduced velocity,the vortex shedding mode could be changed from out of phase 2S(2single) to in phase 2S,and at the same time,the phase difference between the aerodynamic force and the displacement could be changed from 0 to π,which is the so called phase switch phenomenon.By analyzing the phase switch phenomenon,the mechanism for the limited amplitude of the VIV is studied.