不同排列方式和间隙比下双圆柱流致振动特性研究

Research on flow-induced vibration characteristics of two circular cylinders under various arrangements and spacing ratios

采用基于ALE的流固耦合分析方法,将圆柱体振动模型简化为平面双自由度质量-弹簧-阻尼系统,进行了计算参数无关性分析。对不同θ角和间隙比T下的双圆柱流致振动进行数值模拟,并与单圆柱振动计算结果进行比较,得到了不同θ角和间隙比T下中心圆柱的升阻力系数、流场分布和运动轨迹变化情况。通过分析发现小间隙比下由于两圆柱间的相互干扰,改变了中心圆柱的尾涡结构,导致了升力和阻力系数随不同θ角而发生变化;小间隙比下由于两圆柱间的相互干扰影响,均使中心圆柱的轨迹在不同θ角下发生了较大的变化,顺流向的振动频率与单圆柱振动时相比出现了多倍频,导致其运动轨迹发生了变化。

Based on the fluid-solid coupling analysis method of ALE, the cylinder vibration model is simplified as a planar mass-spring-damper system of two-degree of freedom. A calculation of parameter independence analysis is perforned. The flow＇-induced vibration of the t＂wo circular cylinders are simulated under various angles and the spacing ratios r . The θ angle changes between 0 °-180 ° and the spacing ratio r changes between 1.5-4.5. The results are compared ＂with single c y l in d e r v ibra tion to get the changes of the lift and drag coefficient, flow field and the trajector of the center of the cylinder. The results show that, at the small spacing ratios, the change of the lift and drag coefficient under various angles 0 is mainly due to the change of the tail vortex structure, which is caused by the mutual interaction betw-een the two cylinders. Due to the mutual interference between the two cylinders, the trajectory of the central cylinder under various angles 0 is changed greatly under the small spacing ratios. The vibration frequency of the downstream flow is multiple more than the single cylinder, ＂which results in the variation of the movement trajectory.