CAJ | 학술논문

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(2 single)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.
이용작자편제적기우송우합방법적구해기동탄성문제적정서,대원주화방주등전형2유주체적와격진동진행료수치모의.계산결과표명:2유주체적와격진동존재2개쇄정상태,즉저절감풍속조건하적류향쇄정화고절감풍속조건하적횡향쇄정;수착절감풍속적증대,2유주체적선와탈락모식종이향2S(2 single)변화도동향2S;반수착선와탈락모식적전변,기동력화위이지간적상위차출현0→π적극렬변화,즉상위전환현상;통과대상위전환현상진행분석,급출료와격진동시한폭진동적궤리해석.
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(2 single) 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.