Non-Linear Phenomena in Aero-Engine Rotor Vibration

1989 ◽  
Vol 203 (1) ◽  
pp. 25-34 ◽  
Author(s):  
R Holmes ◽  
M M Dede
Keyword(s):  
Frequency Response ◽  
Test Facility ◽  
Medium Size ◽  
Rotor Vibration ◽  
Jet Engine ◽  
Aero Engine ◽  
Non Linear ◽  
Rotor Assembly ◽  
Twin Rotor ◽  
Engine Rotor

This paper describes a test facility which reproduces the essential features of a twin-rotor assembly for a medium-size jet engine. Its purpose is to investigate phenomena experienced in an actual engine, which relate to system non-linearities. These phenomena include subharmonics, combination oscillations and jumps in frequency response. All such phenomena manifested themselves in the test facility and explanations are given as to their cause and possible elimination.

The Vibration of an Aero-Engine Rotor Incorporating Two Squeeze-Film Dampers

1996 ◽  
Vol 210 (1) ◽  
pp. 39-51 ◽  
Author(s):  
R Holmes ◽  
J E H Sykes
Keyword(s):  
Test Facility ◽  
Squeeze Film ◽  
Squeeze Film Dampers ◽  
Aero Engine ◽  
In Series ◽  
Rotor Assembly ◽  
Vibration Signatures ◽  
Vibration Performance ◽  
Subharmonic Resonances ◽  
Engine Rotor

Virtually all previous research on the squeeze-film damping of rotor assemblies has considered the use of only one damper. However, many aero-engine rotor assemblies have at least two dampers and the interplay between them is an important factor in the overall vibration performance of the rotor. The purpose of this paper is to report results on a test facility which simulates the rotor of an aero-engine of the size used to power an executive jet. It draws general conclusions on the application of two squeeze-film dampers (SFDs) to such a rotor, while in the process qualitatively validating a suggested theoretical model of the SFD. The test facility is a three bearing rigid rotor assembly incorporating two sprung bearing supports, each in series with a weakly sealed squeeze-film damper. A range of practical configurations with different SFD static misalignments is studied. Non-linear jump phenomena and subharmonic resonances are demonstrated both experimentally and theoretically for a range of rotor unbalance. The paper is concerned with predicting and measuring rotor-centre responses and vibration orbits and drawing conclusions that are relevant to the designer. It forms a complement to a previous paper (1) in which spectrum analyses of vibration signatures were made.

Vibration Analysis of Civil Aero-Engine Based on Stochastic Resonance Preprocessing

2016 ◽  
Vol 693 ◽  
pp. 1545-1550
Author(s):  
Ying Zhang ◽  
Heng Yu Liao ◽  
Ge Zhao
Keyword(s):  
Stochastic Resonance ◽  
Noise Level ◽  
Vibration Analysis ◽  
Bistable System ◽  
Rotor Vibration ◽  
Short Term ◽  
Aero Engine ◽  
System Output ◽  
Engine Rotor

Stochastic resonance (SR) in the bistable system can reduce the noise level, reveal the waveform’s outline prominently, and improve the quality of the system output. Under the support of SR techniques, the extraction accuracy of the civil aero-engine rotor vibration information is lifted, especially when treating the signals contaminated by heavy noise. Results indicate that the SR signal preprocessing method via tuning the relative parameters is effective to reflecting the real vibration of the aero-engine rotor. It can also monitor the short-term failure phenomenon in the sampling data.

An improved dynamic load-strength interference model for the reliability analysis of aero-engine rotor blade system

2020 ◽  
pp. 095441002097289
Author(s):  
Bingfeng Zhao ◽  
Liyang Xie ◽  
Yu Zhang ◽  
Jungang Ren ◽  
Xin Bai ◽  
...  
Keyword(s):  
Reliability Analysis ◽  
Dynamic Load ◽  
Rotor Blade ◽  
Engineering Application ◽  
Weight Ratio ◽  
System Component ◽  
Aero Engine ◽  
Blade System ◽  
Improved Model ◽  
Engine Rotor

As the power source of an aircraft, aero-engine tends to meet many rigorous requirements for high thrust-weight ratio and reliability with the continuous improvement of aero-engine performance. In this paper, based on the order statistics and stochastic process theory, an improved dynamic load-strength interference (LSI) model was proposed for the reliability analysis of aero-engine rotor blade system, with strength degradation and catastrophic failure involved. In presented model, the “unconventional active” characteristic of rotor blade system, changeable functioning relationships and system-component configurations, was fully considered, which is necessary for both theoretical analysis and engineering application. In addition, to reduce the computation cost, a simplified form of the improved LSI model was also built for convenience of engineering application. To verify the effectiveness of the improved model, reliability of turbojet 7 engine rotor blade system was calculated by the improved LSI model based on the results of static finite element analysis. Compared with the traditional LSI model, the result showed that there were significant differences between the calculation results of the two models, in which the improved model was more appropriate to the practical condition.

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