Analysis of Critical Instability Flowrate of Pipeline Conveying Fluid with Elastic Supports
分析弹性支承输流管道的失稳临界流速

The dynamic stability of pipes conveying fluid with both ends supported elastically is investigated. The vertical vibration modal function of pipeline supported elastically on two ends is derived from the boundary condition of the elastic supported beam.The effect of supporting elastic coefficient,mass ratio,fluid pressure and axial force on critical instability flowrate is calculated and analyzed based on the eigenequation.The numerical results show that the stability of pipe is complicated because the dynamic stability varies with different elastic supporting coefficients and parameters acting on the pipe.Dynamic flutter instability will occur with a certain low elastic coefficient and in some parameter ranges and the static instability will happen under a high elastic coefficient and high parameters acting on the pipe.The critical instability flowrate is proportional conversely to fluid pressure and axial compression force of pipe section,but is proportional to the axial tensile force.