Calculation And Prediction Of Leakage Rate Of W-shaped Metal Seal Ring

W-shaped metal sealing ring is an important part of high-performance aero-engine.Improving the sealing performance of W-shaped metal sealing ring can improve the efficiency of aero-engine,as well as the emission level and life level.The research and development of the W-shaped metal seal ring has become the key to the technological breakthrough of modern aero-engines.Therefore,this paper will focus on the study of of the W-shaped metal seal ring leakage rate calculation and prediction methods.The calculation method of leakage rate of W-shaped metal seal ring is:Firstly,the macro structure of W-shaped metal seal ring is analyzed by finite element method.And then the surface after contact deformation is obtained by microscopic contact analysis.Finally,the surface deformed after contact is used to construct Micro leakage channel,and the leakage rate is obtained by numerical calculation.(1)First of all,the mechanical properties of GH738 are measured through material experiments,and then based on the structure of the W-shaped metal sealing ring and flange surface,the mechanical model of the W-shaped metal sealing ring sealing structure is established,and finally through FEA obtain the compression resilience,contact width and average contact pressure of the W-shaped sealing ring.(2)First,the contact area of the W-shaped metal sealing ring is divided into several calculation units according to the contact width.Based on the characteristic parameters of the rough surface scanned by the electron microscope,the point cloud of the rough surface is generated by using the W-M fractal function,and the point cloud is converted into the rough surface entity through reverse engineering.Based on the contact mechanics,the contact model of rough surface entity was constructed according to the mean contact pressure and boundary conditions.Finally,Abaqus was used to obtain the surface after contact deformation of the rough surface entity,and the results after contact deformation of the rough surface were analyzed,and the characteristics of the real rough surface contact deformation were analyzed.Based on the deformed rough surface generated by the contact model,the leakage microchannels between the rough surfaces were solved by reverse engineering.(3)The flow state of the fluid in the microchannel is determined by the dimensionless parameters of the fluid in the microchannel and air condition parameter.Based on the flow state,the fluid leakage microchannel established above was imported into the Fluent for solution,and the leakage flow of a single calculation unit was obtained.Then,the leakage flow of the entire W-shaped metal sealing ring was calculated,and the relationship between the leakage and various influencing factors was analyzed.Experiments verify the accuracy of leakage rate calculation and analyze the error source.(4)The prediction method of leakage rate of W-shaped metal sealing ring is:based on the leakage rate calculation method mentioned above,the test parameters under working conditions are designed according to the actual working conditions,and the leakage rate under working conditions is calculated.Response surface model and neural network model were used to train test samples,and the prediction model of leakage rate of W-shaped metal seal ring was obtained.The advantages and disadvantages of the two models were compared.