气-液横向流动下悬臂柱体结构涡激振动机理研究北大核心CSCD

针对潜艇侦查望远镜举升水面时产生的涡激振动现象,该文建立了悬臂柱体结构受气-液两种不同横向流作用下的涡激振动理论模型.研究了两种流体不同的分布比和密度比对柱体结构涡激振动行为的影响规律.基于Galerkin法和Runge-Kutta法,得到了柱体结构涡激振动响应的数值结果.研究表明,柱体结构的涡激振动锁频区随着流体分布比的增大而增大,自由端最大幅值随着流体分布比的增大先增大后减小.当分布比为0.5附近时,振幅出现极大值,该极大值随着流体密度比的减小呈现明显的增大趋势.此外,柱体的动力学行为随着流体分布比的变化呈现出周期和多周期等振动模式.该研究可为潜艇侦查望远镜结构的设计与分析提供理论指导意义.

A Study on the Vortex-Induced Vibration Mechanism of Cantilever Cylinders Under Gas-Liquid Cross Flows

Aimed at vortex-induced vibration (VIV) of the submarine reconnaissance telescope lifting above the water surface, a theoretical model for VIV of a cantilever cylinder under the actions of two different cross flows, i.e. gas and liquid, was established. The effects of parameters such as the distribution ratio and the density ratio for these two fluids on VIV responses of the cylinder were studied. Based on the Galerkin technique and the Runge-Kutta algorithm, numerical results of the cylinder vibration responses were obtained. The results show that, the increase of the distribution ratio can widen the lock-in range of the cylinder. The peak amplitude of the cylinder increases first and then decreases with the distribution ratio. The amplitude reaches the maximum value with a distribution ratio of 0.5, and this maximum value will increase with the decrease of the density ratio. In addition, single-period and multi-period motions will occur with the change of the fluid distribution ratio. The present research provides a theoretical guidance for the design and analysis of the submarine reconnaissance telescope.