Numerical Analysis On The Fluid-solid Coupling Vibration Of Hydraulic Pipeline With Elastic Support

Domestic study on large aircraft application is still in early stages，the market demandgap is so big that China is facing unprecedented opportunities and challenges. However，coupling vibration of hydraulic pipeline system tends to cause fracture and fatigue failure，which seriously affects the operation and security of large aircrafts. The pumped periodicpulsation fluid is the main factor of causing fluid resonance and stimulating pipelinesvibrations，and elastic support stiffness is closely related. It is necessary to synthesizeresearch in the two areas so that related topics can be extracted of hydraulic vibrationcharacteristics of piping system.Subject has focused on effect laws on the hydraulic straight pipeline with plungerpump and elastic support，the following research work has carried out.(1) Considering the influence of support stiffness， establish fluid-structureinteraction dynamical model of straight pipeline with variable stiffness elastic support，andsolve its natural frequency in MATLAB using transfer matrix method.(2) Set up finite element model of single straight pipeline in ADINA software，analyze the tendency of FSI natural vibration characteristics for pipeline with differentsupport stiffnes.Results illustrate that each order of FSI natural frequency is growing dueto the increase of support stiffness of the pipeline system，and when the stiffness is morethan107N/m，the natural frequency has similar characteristics comparing the pipelinewith fix support.(3) Analyze the tendency of flow velocity，pressure，surface acceleration，stress andreaction force，under different inlet flow rate due to the plate angle change of plungerpump.Results show that the inherent and response characteristics of pipeline has beensignificantly impacted by support stiffness，while it has been less affected by swash plateangle changes.(4) Analyze the tendency of flow velocity，pressure，surface acceleration，stress andreaction force，under different inlet flow pulse frequency due to plunger pump speedchanges.The change of rpm has complex impact on inherent and response characteristicsof the pipeline. (5) Analyze the tendency of flow velocity，pressure，surface acceleration，stress andreaction force，under different system pressure.Results indicate that when the systempressure，pulsation amplitude of fluid velocity and pressure，surface acceleration andreaction force are all in a growth when the system pressure increases.