Numerical Simulation And Digital Design For Rotating Lip Seal

Rotary lip seals(referred to as lip seals)are widely used in liquid oxygen kerosene engines and are an important basic part to stop the lubricating medium from leaking into the external environment or external impurities from entering the sealing space.The rotating shaft in the engine has extreme working conditions of high speed and high temperature,which requires high sealing performance and structural form of the lip seal,so it is important to master the systematic and accurate lip seal design method.In this thesis,a rubber material high-speed rotary lip seal is used as the research object,and a combination of finite element analysis,numerical simulation analysis and experimental verification is used to investigate the changes of lip seal structural parameters on the sealing performance under high-speed condition.Through the measured cross-sectional dimensions of the lip seal,a two-dimensional axisymmetric model conforming to the actual working conditions of the lip seal was established using ABAQUS finite element analysis software.The effectiveness of the lip seal material and the lip seal spring were simulated by the rubber material mechanical property test and the radial force tester,respectively,to finally obtain the contact pressure distribution and lip stress variation in the lip seal sealing area,which provided analytical data for the subsequent numerical simulation analysis.Combined with the finite element analysis results,the numerical simulation analysis model of flow-solid-thermal multi-physical field coupling was established considering the actual lubrication state and application working conditions of the lip seal.The model is based on Reynolds equation,G-W contact theory model and influence coefficient method for the seal contact interface,while considering the influence of frictional heat at the seal lip.The accuracy of the simulation results was verified with the help of surface micromorphological tests and rotating bench experiments,and the numerical model was supplemented and improved.The numerical simulation model was developed to study the variation of key parameters such as contact pressure distribution,lip temperature,friction torque and leakage rate of oil seal lip with rotational speed.To address the complexity of the lip seal design process,the ABAQUS FEA pre and post-processing was automated by writing Python scripts of the lip seal modeling process,and finally the operation interface was built using MATLAB GUI tools.The user only needs to input the parameters according to the actual application conditions to get the parameters such as leakage rate and friction reflecting the sealing performance,so that the numerical simulation model of the lip seal can be integrated into the engineering application to guide the design of the lip seal and improve the design efficiency of the lip seal.