Research On Measurement And Simulation Of Engine Thrust Test Stand

With the rapid development of modern aerospace industry,the measurement of rocket engine thrust vector has gradually become the focus of the development of engine,and accurate measurement of the thrust vector is important for evaluating the performance of engine.The characteristics of test stand are important factors that affect the accuracy of the measurement.Finite element analysis(FEA)can predict the response of the structure under various load conditions,which is of great significance for the development of the test stand.Test technology of thrust vector is the focus in the field of engine testing.We used to only measure thrust component along the axial in the engine test,while ignoring other components.Therefore,it is urgently needed to develop a thrust measurement device that can accurately measure multiple components.In order to reproduce the true thrust of the rocket engine and improve the measurement accuracy,it is necessary to study the measurement of the thrust of rocket engine and simulate the performance of the test stand.This thesis takes the engine thrust test bench as the main application object,and studys thrust measurement decoupling theory and structural FEA.Based on the principle of theoretical mechanics,the mechanics model of test platform is established,the theoretical calculation method of thrust vector is analyzed and the calculation method of eccentricity parameter is determined.On the basis of multiple linear regression theory,LS method and TLS method are used to decouple the measurement equations,and the decoupling matrices and decoupling accuracy are analyzed according to the SVD method,the minimum singular value method and the Euler-Lagrange approximation principle formula.In the light of FEA theory,partial structure is simplified and the entity segmentation technology is used to complete the map and sweep grid division.ANSYS is used to obtain Stress and displacement cloud map under different conditions,the location of maximum stress is analyzed to give the proposed improvement of structure.The change curve of stress is obtain,the stress variation is determined,the vibration characteristics are studied by modal analysis and the natural frequency and vibration are determined.On the ground of the orthogonal test theory,the orthogonal simulation experiment of structural optimization is conducted,the influence of different structure optimization scheme is obtained and the optimal level combination is determined.The verification test of decoupling algorithm and simulation test are carried out,the decoupling matrix is obtained by different methods and the error of different decoupling methods is analyzed and the accuracy of decoupling algorithm and FEA results are verified.The thrust measurement,decoupling theory and the overall mechanical performance of the test stand are studied by theoretical research,simulation analysis and experimental verification.The test results show the correctness of the thrust test decoupling formula and the finite element simulation analysis result of the test stand.