Data Based Modeling of Aero Engine Vibration Responses

Author(s):  
Manu Krishnan ◽  
Ran Jin ◽  
Ibrahim A. Sever ◽  
Pablo A. Tarazaga
2016 ◽  
Vol 138 (9) ◽  
Author(s):  
Jie Guo ◽  
Yipeng Cao ◽  
Wenping Zhang ◽  
Xinyu Zhang

The engine vibration and noise induced by a valve train element are analyzed through the modeling and experiment method. The valve train dynamics are first studied to make clear the sources of the valve train noise. The component flexibility and inertia of mass are all taken into consideration as well as the contact or impact behaviors. The contact or impact forces are applied on the combined model of a combined structure. The resulting vibration responses at the outer surfaces are considered to be the boundary conditions of the acoustic model. The acoustic model is built by the boundary element method. The analysis results show that the noise induced by the valve train element is mainly in the 500–800 Hz 1/3 octave bands. The noise in this frequency range is related to not only the resonance of oil pan and valve cover but also the overall combined structure stiffness. And moreover, the resonance of the valve train element excited by the harmonic of the camshaft rotational frequency has heightened the noise radiation in this frequency range. The noise in the low-frequency range is determined by the exciting components of the cam profile, and that in the high-frequency range are produced mainly by the valve–seat impact and by the cam–tappet impact. The analysis results are proved well by comparison with the experimental results. Thus, the results are very useful for understanding the source characteristics of valve train noise.


2013 ◽  
Vol 328 ◽  
pp. 463-467 ◽  
Author(s):  
Xiao Bo Liu ◽  
Bei Bei Deng ◽  
Liang Ni Shen

Aiming at the problem about initial clustering center was randomly assigned in K-means clustering algorithm, the improved K-means clustering algorithm based on hierarchical clustering algorithm and K-means clustering algorithm was proposed in this paper. In the improved algorithm, first of all K was calculated by hierarchical clustering. When K was determined, K-means clustering was implemented. The results of the aero-engine vibration data clustering shown that not only the k value was to quickly and accurately determined, but also the number of clusters can be reduced and higher computing efficiency can be attained by the improved K-means clustering algorithm.


2007 ◽  
Vol 347 ◽  
pp. 323-328
Author(s):  
Kai Xiong ◽  
Dong Xiang Jiang ◽  
Yong Shan Ding ◽  
Kai Li

RBF neural network and support vector machine (SVM), two Artificial Intelligent (AI) methods, have been extensively applied on machinery fault diagnosis. Aero-engine, as one kind of rotating machine with complex structure and high rotating speed, has complicated vibration faults. As one kind of AI methods, RBF neural network has the advantages of fast learning, high accuracy and strong self-adapting ability. Support vector machine, another AI method, only needs a small quantity of fault data samples to train the classifier and does not need to extract signal features. In this paper, the applications of two AI methods on aero-engine vibration fault diagnosis are introduced. Firstly, the principles and algorithm of both two methods are presented. Secondly the fundamentals of two-shaft aero-engine vibration fault diagnosis are described and gotten the standard fault samples (training samples) and simulation samples (testing samples). Third, two AI methods are applied to the vibration fault diagnosis and obtained the diagnostic results. Finally, the advantages and disadvantages of the two methods are compared such as the computing speed, accuracy of diagnosis and complexity of algorithm, and given a suggestion of selecting the diagnostic methods.


2021 ◽  
Vol 34 (1) ◽  
Author(s):  
Xiantao Zhang ◽  
Wei Liu ◽  
Yamei Zhang ◽  
Yujie Zhao

AbstractThe design of aircraft hydraulic pipeline system is limited by many factors, such as the integrity of aviation structure or narrow installation space, so the limited clamp support position should be considered. This paper studied the frequency adjustment and dynamic responses reduction of the multi-support pipeline system through experiment and numerical simulation. To avoid the resonance of pipeline system, we proposed two different optimization programs, one was to avoid aero-engine working range, and another was to avoid aircraft hydraulic pump pulsation range. An optimization method was introduced in this paper to obtain the optimal clamp position. The experiments were introduced to validate the optimization results, and the theoretical optimization results can agree well with the test. With regard to avoiding the aero-engine vibration frequency, the test results revealed that the first natural frequency was far from the aero-engine vibration frequency. And the dynamic frequency sweep results showed that no resonance occurred on the pipeline in the engine vibration frequency range after optimization. Additionally, with regard to avoiding the pump vibration frequency, the test results revealed that natural frequencies have been adjusted and far from the pump vibration frequency. And the dynamic frequency sweep results showed that pipeline under optimal clamp position cannot lead to resonance. The sensitivity analysis results revealed the changing relationships between different clamp position and natural frequency. This study can provide helpful guidance on the analysis and design of practical aircraft pipeline.


Machines ◽  
2021 ◽  
Vol 9 (9) ◽  
pp. 189
Author(s):  
Yue Chen ◽  
Jiwen Cui ◽  
Xun Sun

The assembly quality of the multistage rotor is an essential factor affecting its vibration level. The existing optimization methods for the assembly angles of the rotors at each stage can ensure the concentricity and unbalance meet the requirements, but it cannot directly ensure its vibration responses meet the indexes. Therefore, in this study, we first derived the excitation formulas of the geometric and mass eccentricities on the multistage rotor and introduced it into the dynamics model of the multistage rotor system. Then, the coordinate transfer model of the geometric and mass eccentricities errors, including assembly angles of the rotors at all stages, was established. Moreover, the mathematical relationship between the assembly angles of the rotors at all stages and the nodal vibration responses was established by combining the error transfer model with the dynamics model of the multistage rotor system. Furthermore, an optimization function was developed, which takes the assembly angles as the optimization variables and the maximum vibration velocity at the bearings as the optimization objective. Finally, a simplified four-stage high-pressure rotor system was assembled according to the optimal assembly angles calculated in the simulations. The experimental results showed that the maximum vibration velocity at the bearings under the optimal assembly was reduced by 69.6% and 45.5% compared with that under the worst assembly and default assembly. The assembly optimization method proposed in this study has a significant effect on the vibration suppression of the multistage rotor of an aero-engine.


Sign in / Sign up

Export Citation Format

Share Document