Simulation And Analysis Of The Fluid And Solid Interaction Vibration In External Pipeline System Of The Aeroengine

The external piping system of aero engine is one of the most important accessory devices of aero-engine.It acts as the transmission channel of fuel and lubricating oil in the engine,and connects all parts of the aero engine to an organic whole.The working environment of high temperature,high pressure and high rotation rate of the engine is easy to break the external pipeline system,and when it happens,the result is serious.More than 50% of the malfunction of the aero engine is caused by the failure of the external pipeline.The problem of fluid solid interaction vibration of the external pipeline is one of the main reasons that causes the failure of the pipeline.Therefore,it is of great significance to carry out the simulation and analysis of the fluid solid interaction vibration of the aero engine external pipeline.First,the basic pipeline model is derived,which is 14 partial differential equations for the fluid solid interaction of the pipeline.The method for soving the 14 partial equations are given,and so is the mesh method for how to determine the step of time.Then summarize the typical boundary element type of pipeline system,the physical model of its corresponding boundary conditions,the boundary element equations are given.Combined with the characteristic line equations,the parameters of the fluid solid coupling in the pipeline system can be obtained in the time domain.The theoretical basis is laid for the numerical simulation analysis of the vibration response of the rear filled pipe system.Based on the C++ language,the software for the simulation and analysis of the fluid solid coupling vibration of the aero engine external pipeline is developed.The correctness of the software is verified by literature example.The method of solving the problem of fluid solid coupling vibration in pipeline is introduced by the method of ANSYS,and the fluid solid coupling vibration of a RPV system is simulated and calculated.The natural frequency of the liquid filled pipe is studied by using the MOC-FFT method.First,the time domain response of the pipeline system is obtained by using the characteristic line method.The natural frequency of the fluid solid coupling vibration pipeline system is obtained by analyzing the time domain response by using the fast Fourier transform.The dynamic pressure characteristic test is carried out for a fuel pipeline system of an aero engine.It show that under the same condition,the pressure curves of different pipeline are similar,near the entrance the pressure value is higher;for the same measuring point,and the same base vibration acceleration,with the increase of fluid pressure flow,the pressure in the pipe is reduced;for the same measuring point,and the same flow,the amplitude of the fluid pressure fluctuates is more than two times that of the zero acceleration when there is acceleration.When the base acceleration is changed,there is no obvious change in the center of fluid pressure fluctuation.The experimental model is theoretically calculated by software.The pressure calculation results agree well with the test results.When FFT is used to process the pressure data,the fundamental frequency of pressure fluctuation and the deviation of test as 1.63% is obtained.