Modeling And Analysis Of Hydraulic Pipe FSI System Of Aero Engine

The hydraulic pipe of aero-engine is mainly used to transport fuel, lubricating oil and other media such as air. It is an important part of accessories system on aero-engine. At the same time, the working environment of hydraulic pipe is quite bad. Once the pipe fracturing, the consequence is extremely serious. After previous investigation and study, the breakdown of aero-engine is mostly due to hydraulic pipe rupture, and fluid-structure interaction (FSI) vibration of the pipe is one of the main reasons for the cause. Therefore, the reliability of hydraulic pipe directly affects the engine’s performance and security. There is an important significance to research the FSI vibration mechanism and inherent characteristics of hydraulic pipe on the aero-engine.This research aims at the vibration mechanism of hydraulic pipes on the aero-engine so as to solve the oil leakage and crack problem of resonance. So accidents can be avoided. Based on Newton method, the nonlinear differential equation of FSI vibration has been established, the equation include visco-elastic coefficient and fluctuating flow factors, than the dimensionless equation was got. The influence of mass ratio, velocity of fluid and axial force on the natural frequency were researched by analyze the FSI vibration equation. Discretize the differential equation of the pipe motion by using Galerkin method. And then, by using the orthogonality of modal functions, the standard equation of the first order differential equations were got; the mathematical expression of pipe system critical velocity was deduced; the differences between complex modal Galerkin method and method were compared; the relationship curves between the natural frequency and parameters such as mass ratio were got. And the response of vibration amplitude of the pipe to aero-engine casing stimulation was analyzed. Through the numerical simulation of the aero-engine hydraulic pipe vibration, the response curve and the phase plane portrait of the system were obtained. Then, the stability of the system was analyzed. The pipe vibration response was obtained by experiments at several simulate frequency. And the conclusion of the experiment was consistent with the theory.The conclusions of this paper correspond with the results obtained of FSI vibration of pipe conveying fluid. And the paper has better simulated the work environment of hydraulic pipe on aero-engine. The research can provide references for designing hydraulic pipe system of the aero-engine.