Research On Gas Turbine Engine Units Vibration Diagnostics Based On Mutual Vibration Influence

A fight against vibration has become an important condition for ensuring high quality engines.It is carried out at the stages of design,development,serial production and operation of engines.Combating vibration requires a combination of design and experimental methods.The combination of design and experimental methods allows to increase the degree of confidence in the calculation results and on their basis to identify the most dangerous sections of the structure for further research or to make changes to the structure when it is modified,which arise when considering issues related to the assessment and extension of its performance.The first chapter of the work describes the mechanisms of occurrence and propagation of vibration.The processes of the mutual vibrational influence of the nodes of an air-jet engine are analyzed.The methods of registration and ways to eliminate excessive vibration are also considered.The second chapter describes in detail the problem of vibration,the reasons for the appearance,and the consequences for the design of air-jet engines.Modern methods and methods for registering a vibration signal in engine components are considered.The process of diagnostics of a modern engine is considered in stages.The causes of possible errors in measuring vibrations are described.The third part of the work is devoted to the design and construction of an experimental setup and the process of obtaining data for analysis.The fourth part is considered the task of finding the cause of the high vibrations in the area vibrogram characteristic of the vibration of the flexible shaft remote box engine units.A case of the mutual influence of the vibratory box remote units,propulsion units and boxes piezoelectric vibration sensor.based on data that were obtained from sixteen AL-31 F engines that were serviced with a high vibration problem.A broadband spectral analysis of vibration on the remote unit box was used to reveal the relationship between the appearance of intense highfrequency vibrations associated with the harmonics of the pump and the appearance of an intense low-frequency noise sensor in the operating frequency range,which in some cases causes increased overall vibration of the unit remote box.The excitation mechanism of these oscillations is associated with the device and the operation of the vibration sensor.This dissertation work offers a method for solving the problem of increased vibration in the remote box of the units of the AL-31 F air-jet engine,which will increase the uptime,reduce the cost of diagnostics and repair.