立管涡激振动高阶响应研究（英文）

Investigation on Higher-Order Responses of Vortex-Induced Vibration for a Mounted Cylinder

由于高阶响应对结构涡激振动存在显著影响,文中在考虑其影响的前提下利用经典Van der Pol尾流振子模型研究了立管在均匀流中的涡激振动特性。在尾流振子与结构模型的相互作用中同时考虑了一阶响应和高阶响应的影响,从而推导了一种考虑了一阶—高阶响应的涡激振动模型。并在此基础上,分析了考虑位移、速度和加速度三种不同右端耦合项作用下的响应特性。此外,还针对不同的质量阻尼比,比较了考虑高阶响应影响和未考虑高阶响应影响情况下系统的涡激振动特性。结果表明,考虑一阶—高阶响应的理论模型能更精确地反映该系统的振动特性。尾流振子和立管的运动幅值都有一定程度的增大。尽管计算结果显示高阶响应比一阶响应小若干个量级,但是不可以忽视高阶响应,因为它对一阶响应存在明显的影响。

According to its significant effect on the structural vortex-induced vibration(VIV),higher-order responses of VIV on a mounted cylinder in a uniform flow is investigated on the basis of the classical Van der Pol wake oscillator.Both the first-order and higher-order responses are discussed for the interaction of a wake oscillator and a linear spring-mass-damper system.Equations are established to model the mechanism of VIV concerning the first-plus higher-order responses,and the analysis of the dynamical performance includes displacement,velocity and acceleration coupling terms.Moreover,comparison with the motion characteristics that only take the first-order response into account is made for various mass damping ratios.The results show that the new model based on the first-plus higher-order responses can characterize the behavior of VIV more precisely,such as the amplitudes of structural vibrations.The motion amplitudes of the wake oscillator and the cylinder enlarge to certain degrees,respectively.Although features of the higher-order responses including structural motion amplitude are several orders of magnitude smaller than that of the first-order response,it is not negligible according to its apparent influence on the first-order response.