Research And Optimization Design Of High-pressure Reciprocating Sealing Mechanism Of Landing Gear Buffer

As a key functional component of landing gear buffer,the performance of reciprocating seal directly affects the takeoff and landing performance of the aircraft.During the landing of the aircraft,the landing gear is subjected to extremely shock loads,which leads to a sharp increase in the working pressure of the buffer reciprocating sealing system.Therefore,the research and performance analysis of high-pressure reciprocating sealing mechanism have an important impact on improving the bearing capacity and service life of the landing gear.In this thesis,the 2K type step seal commonly used in landing gear buffers is the research object,and the dynamic sealing performance analysis and structural optimization design of step seal under ultra-high pressure conditions are carried out through the combination of experimental testing and numerical simulation.Firstly,the Map Solution method is used to obtain the convergence solution of the finite element simulation under ultra-high pressure condition,which solves the problem of large mesh deformation with the help of the restart function of ABAQUS software and the mesh reconstruction technology of Hypermesh software.Compare the simulation results with and without the Map Solution method to verify its feasibility.Then,the hybrid lubrication model of reciprocating sealing system is established to quantitatively predict the performance parameters such as the inner seal,stroke net flow and friction under different working conditions.The model considers the coupling of fluid flow,microscopic deformation of rough peaks,macroscopic deformation of the sealing ring,and system heat transfer.Through the reciprocating sealing bench test,the actual working conditions of the step seal are simulated,and the experimental data and simulation results are compared to verify the accuracy of the theoretical model.Finally,based on the fluid-solid-thermal multi-field coupling model and combined with the orthogonal experimental design method,the structure and performance optimization of step seal are carried out.According to the material-level friction and wear test data and Rhee classic wear equation,the change law of the structural contour and sealing performance of the step seal with the total reciprocating stroke is studied,and judge whether the service life of the optimized step seal meets the expected requirements.The results of this thesis will provide a theoretical basis for the performance analysis of high-pressure reciprocating seals,and provide technical support for the design and selection of reciprocating seals of landing gear buffers.