Research On Transient Vibration Characteristics Of Aeroengine Hydraulic Pipeline

Aircraft hydraulic pipeline is an important pipeline structure of the aircraft.The reliability of hydraulic pipeline work is related to the safety of the hydraulic system and even the flight of the aircraft.The engine-driven pump is the main energy-supply pump of the aircraft’s hydraulic system.It transmits pressure oil to various hydraulic users of the aircraft through hydraulic line.Because the hydraulic oil at the pump outlet is not a steady-state pressure oil,it is a high-pressure pressure oil that transiently pulsates.The impact of such transient excitation on the hydraulic pipeline of the engine and the pulsation excitation often cause pipeline failure and affect the flight safety of the aircraft.Therefore,it is of great significance to study the operating characteristics of the enginedriven pump and its outlet hydraulic pipeline,and to reduce the pressure pulsation and vibration energy of the hydraulic pipeline,to improve the stability of the aircraft hydraulic pipeline system.First,the composition of the mainstream civil aircraft hydraulic system and the functional principles of key hydraulic components are analyzed.Based on the structural characteristics and working principle of the engine-driven pump in the hydraulic system,the working characteristics of the engine-driven pump are studied,and the flow pulsation and pressure pulsation are established Mathematical calculation model.Then,a simulation model of the important components of the engine-driven pump is established in the AMESIM software.The pump model is simulated and solved,and the pressure pulsation function expression of the hydraulic oil at the pump outlet is obtained.Then,based on the theory of fluid-structure interaction,a mathematical model for fluid-structure interaction vibration of hydraulic pipelines was established,and the pipeline and fluid models were established through ANSYS software.The pressure pulsation function obtained in the research was substituted into the ANSYS fluid model to realize data transfer.The dynamic response of the hydraulic pipeline under pressure pulsation was used,and modal analysis and harmonious response analysis were performed.Finally,based on the research results,the potential problems of the hydraulic pipeline at the outlet of the engine-driven pump are analyzed,and multiple optimization schemes based on the clamp constraint method are established.The optimization results of multiple schemes are compared and analyzed.An optimization method to reduce the vibration level of the engine’s hydraulic lines.The thesis establishes the calculation model of flow pulsation and pressure pulsation of engine-driven pump,which enriches the theoretical basis of numerical calculation of aircraft engine-driven pump.Based on the research results,a method for optimizing the vibration of the aircraft engine driven pump pipeline system can provide suggestions and references for practical engineering applications.