不同质量比对刚性圆柱体涡激振动振幅的影响

Effect of Response of Cylinder VIV with Different Mass Ratio

涡激振动发电装置是一种能够捕获浅海区域低流速海流能的新型能源装置,为了在不同海况下均能高效地对能量进行转换,需要对振动参数进行探讨,因此文章对不同质量比下的振动响应和能量两方面进行了分析。结合尾流振子模型和结构振动模型,得到双自由度涡激振动耦合模型,将Stappenbelt试验设置输入该模型,模型计算结果与其试验结果吻合,验证了模型的正确性。对中低质量比、超低质量比和高质量比三种条件下的柱体涡激振动响应进行分析,结果表明,中低质量比条件下,振幅和频率锁定区间宽度随质量比增加而减小;超低质量比条件下,顺流向无量纲振幅接近1,无法忽略,双向最大振幅发生在约化速度Ur=6附近;高质量比条件下,最大振幅所对应的约化速度随着质量比的增加而增加,顺流向第二次波峰消失,横向出现两次波峰。

Devices to generate energy with the VIV is a new energy device used to capture ocean current energy in shallow sea areas with low velocity. In order to convert energy efficiently in different conditions, the parameters that effect vibration need to be discussed. The mass ratio in terms of energy and vibration response is analyzed in this paper Combining wake oscillator model with structural vibration model, two degrees of freedom vortex-induced vibration coupling model are obtained. After importing the Stappenbelt into this model, the result coincides with their experimental results. The correctness of the model is verified. Cylinder vortex-induced vibration response of the three different conditions is studied, namely low mass ratio, ultra-low-mass ratio and high mass ratio, the results showed that in low mass ratio condition, the amplitude and width of lock-in region increases with the mass ratio small; in ultra-low-mass ratio condition, the dimensionless amplitude of in-line close to 1, so the effect of in-line cannot be ignored, the maximum amplitude of 2-DOF occurs near reduced velocity Ur = 6; in high ratio condition, the maximum amplitude corresponding to the reduced velocity increase with the increase of mass ratio, the second peak of in-line disappeared and peak of cross-flow appears twice.