Influence Of High And Medium Pressure Flow And Pressure Fluctuation On Sealing Performance Of Aircraft Hydraulic System

In the airborne hydraulic system,as an important part of pipeline connection,the leakage of hydraulic oil flow through the pipeline joint will seriously affect the normal operation of the whole hydraulic system.Therefore,it is of great value to study the sealing performance of the sealing ring of the pipeline joint.The output flow of the axial piston pump in the hydraulic system is fluctuating.When the impedance of the system is met,the pressure fluctuation will produce impact damage to the pipe joint,which will increase the oil leakage.Considering that the sealing ring belongs to hyperelastic material,it can effectively alleviate the impact damage by introducing the sealing ring into the pipe joint seal.Based on the further improvement of Y-ring,a new type of sealing ring is designed independently,which is suitable for the sealing of pipe joints.The excellent sealing performance is analyzed and some progress has been made,including the following aspects:aiming at the instantaneous output flow of the axial piston pump,the instantaneous flow change of a single plunger is analyzed,and the total instantaneous output flow of the plunger pump is obtained by superimposing the plungers in the oil discharge area.The total instantaneous output flow curve is analyzed by the numerical simulation platform MATLAB.To further verify the accuracy,the axial piston pump model is built and verified by the hydraulic virtual platform AMESIM.In order to study the fluid pressure fluctuation in pipeline,a fluid model of pipeline connection and pipeline is established.With the total instantaneous output velocity of plunger pump as the inlet condition of internal fluid and different back pressure gradients as the outlet,the pressure fluctuation of internal fluid at the inlet and sealing chamber is analyzed by CFX.A simplified model of the sealing structure of pipe joint is established,and the stress changes of the sealing ring in the three stages of pre-sealing,compression and fluid fluctuating pressure loading are analyzed.The Von Mises stress of the sealing ring and the contact stress of the main sealing surface in the stage of fluid fluctuating pressure loading are studied.The failure changes and sealing performance of the sealing ring are discussed.At the same time,the sealing structure models of different pipe joints are established and compared.Considering the coupling effect between hydraulic oil and pipeline,the sealing performance of sealing ring is analyzed by one-way fluid-structure coupling method.A case study based on 23MPa is carried out to verify the accuracy of the previous research method.