Design Of Simulated Aero Engine Dynamics Test Stand And Research On Rotor Failure

Vibration problems and rotor dynamics are quite complex for the aero-engine.Theoretical calculations cannot meet the engineering requirements anymore.Therefore,it is of great significance to develop an aero-engine simulator that can reflect the vibration characteristics and rotor dynamic characteristics,as well as a rotor dynamics test platform.In addition,there could be errors in the process of engine processing and assembly,which may cause failures such as unbalance,misalignment and rubbing during rotor operation,resulting in excessive vibration of the engine and failure to operate normally.Therefore,it is of great significance to eliminate the failure and ensure the normal operation of the rotor by analyzing the characteristics of the vibration signal.Firstly,an aero-engine rotor testbed with a rotating speed exceeding 10,000 rpm was designed.The main design parameters were given and the strengths of the relevant structures was checked.Secondly,an aero-engine simulator including two parts,the gas generator rotor,and static components,was designed.The strengths of the main structural components were checked using finite element(FE)method and the Spey MK202 engine stress standard(EGD-3).The support stiffness were calculated and the critical speeds of the gas generator rotor was calculated.Finally,the effects of imbalance,misalignment,and rubbing on the dynamic responses were studied based on a two-disk rotor model and the designed aero-engine simulator.The Newmark-β method was used to solve the system dynamics.The main contents of this thesis are as follow:1.An aero-engine rotor testbed with a rotating speed exceeding 10,000 rpm was designed.A complete constructing plan and the main technical parameters were formulated,and the designed maximum speed was 47000 rpm.The testbed includes a cabin,a power system,a hydraulic system,and a vacuum system.The design of an aero-engine simulator was carried out subsequently.The simulator contains two parts,the gas generator rotor and the static components.The strengths of the main structural parts of the rotor was verified by ANSYS using The Spey MK202 engine stress standard(EGD-3).The support stiffness and the casing support were calculated.The stiffness and the critical speed of the rotor were calculated using Samcef.The first three critical speeds were9146 rpm,25685rpm and 106854 rpm,respectively.2.A two-disk rotor model with coupled faults was established.The Newmark-β method was used to solve the system dynamic response.The effects of typical faults such as imbalance,misalignment,and rubbing on the dynamic responses were studied.The results show that the rotation frequency,frequency division and multiple frequency components appear in the frequency diagram for the rotor with rubbing fault.The amplitudes of the partial frequency division and multiplication frequency were greater than that of the rotation frequency when the rubbing was severe.The whirl orbit of the system was in the shape of "droplet" and "banana",and the frequency components were mainly the rotation frequency and the double frequency.The rotor system with misalignment-impact coupling failure was misaligned at a certain misalignment angle.At a certain speed,when the misalignment angle was small,the system fault was mainly rubbing faults and the frequency component was the rotation frequency and multi-frequency.When the misalignment angle was large,the system fault was misalignment fault.The frequency component was mainly the rotation frequency and the double frequency.3.The system dynamics equations of the gas generator rotor simulator with coupled faults was also established.The dynamic characteristics of the system with unbalanced,misaligned and rubbing faults were studied.The Newmark-β method was used to solve the dynamic response,and the effects of speed and misalignment angle on the system dynamic response were studied.The results show that the frequency diagram and frequency doubling components appear in the spectrum diagram of the rotor system with rubbing fault.The frequency diagram and frequency doubling were mainly in the spectrum diagram of the rotor system with misalignment fault.Frequency conversion and octave components appear in the system spectrum,while the frequency octave components,especially the even frequency octave components,increase significantly.In this thesis,the structural design scheme of a dynamic rotor test platform with a rotating speed exceeding 10,000 rpm was formulated.The design of an aero-engine simulator including a gas generator part and static components were conducted.Investigations on the effects of imbalance,misalignment,and rubbing on the dynamic responses of a two-disk rotor as well as the designed aero-engine simulator were carried out.The research results had important reference significance for the design of the rotor test bench,the analysis of the fault type and the normal operation of the rotor.