旋转悬臂管道流固耦合振动分析

Dynamics Analysis of Rotating Cantilevered Pipe Conveying Fluid

旋转悬臂输流直管,结合了输流管道和旋转梁的工作特点,在旋转装置中应用广泛,其振动现象对系统的稳定性和可靠性有着重要的影响。针对旋转悬臂输流直管,采用哈密顿方法推导了旋转悬臂输流直管的线性振动微分方程,应用小波有限单元法离散微分方程,构建了旋转悬臂输流直管面内和面外振动的小波单元矩阵。通过分析面内和面外振动的临界流速,表明转速能够增大临界流速曲线的稳定区域,对于质量比相同时,面外的临界流速大于面内的,且随着转速的增大,面内面外的临界流速差值增大。在流速不断增大时,面内振动先于面外发生失稳,对于含有充液管道的旋转机械设计有着参考价值。

Rotating cantilever pipe conveying fluid is widely used in rotating machines,which combines the characteristics of fluid-conveying pipe and rotating beam.The vibration has an important effect on the stability and reliability of the system.The linear vibration differential equation of the rotating cantilever pipe conveying fluid is derived by using Hamiltonian method.The wavelet finite element method is used to discrete the differential equation,and the wavelet element matrix of the in-plane and out of plane vibration of the rotating cantilever pipe is constructed.By analyzing the critical velocity of in-plane and out-of-plane vibration,it is shown that the rotational speed can increase the stable region of critical velocity curve,and for the same mass ratio,the out-of-plane critical velocity is greater than in-plane critical velocity.And with the increase of angular velocity,the difference between in-plane and out-of-plane critical velocity increases.When the flow velocity increases,the instability of in-plane motion becomes instability early,which is valuable for the design of rotating machines.