基于改进尾流振子模型的柔性圆柱体涡激振动响应特性数值研究

Numerical study of response performance of vortex-induced vibration on a flexible cylinder using a modified wake oscillator model

基于改进的尾流振子模型对柔性圆柱体涡激振动响应特性进行了数值研究,先分别建立了柔性圆柱体结构振子模型以及尾流振子模型,随后将二振子模型进行耦合。研究中通过改变无量纲张力、细长比以及质量比等无量纲参数,对柔性圆柱体的振幅比、相位角、频率比以及位移响应时间特性等参数进行了分析。分析结果表明:柔性圆柱体涡激振动响应特性呈现典型的行波特性,行波传播速度随着无量纲张力的增加而呈现上升趋势;行波传播速度随着细长比的增加呈下降趋势。随着无量纲张力以及细长比的增加,位移与升力之间的相位角会发生突变,突变点均发生在振动频率经过固有频率处。

Numerical study was conducted for the response performance of VIV of a flexible cylinder based on a modified wake oscillator model. The structure oscillator model of a flexible cylinder and wake oscillator model were established,and then the two models were coupled. Parameters analyses of non-dimensional displacement,phase angle,frequency ratio and displacement fluctuation characteristics were executed by changing non-dimensional tension,aspect ratio and mass ratio. The analysis results indicate that the VIV response of a flexible cylinder has an obvious travelling wave behavior. The propagation speed increases as non-dimensional tension increases and aspect ratio decreases,respectively. The phase angle has a sudden transition with increased non-dimensional tension and aspect ratio. The sudden transition appears at the point when the vibrating frequency passes the natural frequency.