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Yu H.,Qingdao Branch of Naval Aviation Engineering Institute | Deng Y.,Nanjing University of Aeronautics and Astronautics | Xia C.,Nanjing University of Aeronautics and Astronautics | Fu X.,Nanjing University of Aeronautics and Astronautics | Huang G.-P.,Nanjing University of Aeronautics and Astronautics
Hangkong Dongli Xuebao/Journal of Aerospace Power | Year: 2013

The effect of the tip leakage on the flow field structure and turbine performance of a 78.4 mm diameter centimetre-level high subsonic micro axial flow turbine of a micro turbine engine(MTE) prototype was analyzed by numerical simulation. Results show that the relative tip clearance size of micro axial turbine is within the range of 3.1%-4.6%, which is higher than that of conventional axial flow turbine. The effect of tip leakage vortex extends towards the mid of the vanes, of which the leakage losses account for 35% of total losses of the turbine stage, showing a significant increase compared to the conventional axial flow turbine. Studies on the impacts of the law of the gap size of the centimetre-level high subsonic micro axial flow turbine have shown that, once the gap size for each increases by 1% of the blade height, the efficiency will decrease up to 1.9%, which is more distinct than the conventional turbine. Finally, an optimum gap size (0.4 mm) was determined due to the restrictions of engineering installation (centrifugal deformation, thermal deformation, bearing clearance, machining and assembly errors, etc), and the performance parameter of the impeller was acquired by numerical simulation: total pressure ratio of 2.12, efficiency of 0.87, mass flow of 0.35 kg/s.


Xu K.-J.,Qingdao Branch of Naval Aviation Engineering Institute | Ren S.,Nanchang Hangkong University | Qin H.-Q.,Qingdao Branch of Naval Aviation Engineering Institute | Li Z.-N.,Nanchang Hangkong University
Zhendong yu Chongji/Journal of Vibration and Shock | Year: 2015

Based on rapid convergence and good global search capacity, a new method for rolling bearing fault diagnosis was presented by combining quantum genetic algorithm(QGA) and spectral kurtosis(SK). The original signal's SK gained by the primary band-pass filtering was taken as the fitness function of QGA to redesign the optimal band-pass filter. Then the original signal was filtered with the optimal band-pass filter redesigned. The characteristic frequencies of rolling bearing faults could be nicely obtained with the envelope analysis. The method was used to analyze actual testing signals. The results showed that the SK values obtained with the new method increase obviously, the envelope spectral lines of the filtered signals and the characteristic frequencies of faults are much clearer than those of the traditional SK results; the accuracy of the new method is not dependent upon the positions of sensors. ©, 2015, Chinese Vibration Engineering Society. All right reserved.


Xu K.-J.,Qingdao Branch of Naval Aviation Engineering Institute | Qin H.-Q.,Qingdao Branch of Naval Aviation Engineering Institute | Jiang L.-P.,Qingdao Branch of Naval Aviation Engineering Institute
Zhendong yu Chongji/Journal of Vibration and Shock | Year: 2011

Here, EMD and HHT were applied to rotor-case vibration signal analysis of an dero engine. The vibration signals from an aero engine when it was in bench tests were analyzed. The results showed that the two methods can clearly reproduce the rubbing fault process between rotor and stator with change of rotating speed and sampling period. They could obtain the rubbing information in time and frequency domains to overcome the shortcoming of Fourier transormation only displaying the information in frequency domain. It also was shown that the marginal spectrum can display the distribution of a system's frequency and amplitude more really.


Yu H.,Qingdao Branch of Naval Aviation Engineering Institute | Sun H.,Qingdao Branch of Naval Aviation Engineering Institute | Yan L.,Qingdao Branch of Naval Aviation Engineering Institute | Zhang K.,Qingdao Branch of Naval Aviation Engineering Institute
Lecture Notes in Electrical Engineering | Year: 2014

The study of the condition monitoring system was the basis of the condition based maintenance which is the mode adopted by the advanced aero-engine. Referring to the work and maintenance features of a certain type of turboshaft engine, the engine condition monitoring system based on flight data has put forward the function, structure, and monitoring methods. It has been shown that the system is very effective and reliable to analyze the state of the engine health and locate the faults. © 2014 Springer-Verlag.


Qin H.,Qingdao Branch of Naval Aviation Engineering Institute | Xu K.,Qingdao Branch of Naval Aviation Engineering Institute | Sui Y.,Qingdao Branch of Naval Aviation Engineering Institute | Yu S.,Qingdao Branch of Naval Aviation Engineering Institute
Zhendong Ceshi Yu Zhenduan/Journal of Vibration, Measurement and Diagnosis | Year: 2011

Based on the characteristics of random, gray and fuzzy information in the process of rolling bearing fault pattern recognition, a new fuse frame is presented by the view of information fusion. The characteristic vectors are calculated from wavelet, amplitude and frequency domain information, and the evidence theory is used. The diagnose result is gained by Hidden Markov Mode. Then, the recognition results from the view of gray and fuzzy are obtained. Results are fused so that rolling bearing fault pattern can be identified from multi-angle of view information. The fuse frame is applied to rolling bearing real test vibration data. The result shows that the class validity probability can be remarkably more advanced from multi-angle of random, gray and fuzzy information than single information.

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