有限流体域内不同位置处的柔性管涡致振动机理研究

Research on Vortex-Induced Vibration of Flexible Pipes at Different Locations in a Limited Fluid Domain

针对有限流体域内柔性管的涡致振动问题,将柔性管离散为若干空间梁单元,流体域采用实体单元离散,建立了有限流体域内柔性管系统的流固耦合模型及数值计算方法,设计并加工圆柱流体域内柔性管振动专用实验装置,采用GWT-2B双轴加速度传感器对柔性管的振动进行监测,并与数值模拟结果进行对比,吻合程度较好.基于该文的模型和方法,对圆柱流体域内不同位置处柔性管的涡致振动机理进行研究.结果表明,柔性管偏离入口流速位置的角度越大,越容易发生流体弹性不稳定性,柔性管的振动愈剧烈;而正对入口流速的位置,不易发生流体弹性不稳定性,柔性管振动减弱.

In view of the vortex-induced vibration of flexible pipes in a limited fluid domain,the flexible pipe was numerically discretized into 3D beam elements and the fluid body was discretized into solid elements.The fluid-structure interaction model and numerical calculation method were set up for the flexible pipe in the limited fluid domain.A special experimental device was designed and machined for the test of flexible pipe vibration in the cylindrical fluid container.In the experiment,the GWT-2B-axis accelerometers were used to monitor the vibration.Comparison between the tested vibration results and the numerical simulation results showed a good degree of agreement.Based on the established model and methods,the vortex-induced vibration mechanism was studied for the flexible pipe at different locations in the cylindrical fluid domain.The results show that,the bigger the deviation angle at which the flexible pipe is located from the inlet velocity is,the easier the fluid elastic instability is to occur and the more intense the flexible pipe vibration is.However,when the flexible pipe is opposite the inlet velocity,the fluid elastic instability is less easy to occur and the flexible pipe vibration is weakened.