The existence of the aeroengine casing,limited monitoring points,and multi-fault characteristics make obtaining the rotor’s vibration transmission characteristics challenging,resulting in difficulties accurately iden...
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The existence of the aeroengine casing,limited monitoring points,and multi-fault characteristics make obtaining the rotor’s vibration transmission characteristics challenging,resulting in difficulties accurately identifying the rotor *** paper utilizes a high-frequency composite sensor to monitor the engine’s blade tip clearance(BTC)and extracts unbalanced information from BTC signals for rotor dynamic balancing,while avoiding the need for the once per revolution(OPR)***,the vibration characteristics of the rotor-blade system under multi-fault conditions are ***,based on BTC measurement,a none OPR method and an unbalance identification method are proposed,in which the radial vibration of the blade tip in the BTC signals at different speeds is extracted and operated in the time domain to obtain the rotor unbalanced vibration,the signal is reconstructed,and cross-correlation analysis is used to accurately identify the magnitude and phase of the unbalanced ***,a rotor test bench is utilized for experimental *** results reveal that the dynamic balancing method based on the BTC signal can more precisely identify the rotor unbalance than the traditional rotor dynamic balancing *** application of this technique will effectively improve engine health management and fault prediction.
Effective fault characteristic extraction is crucial for the diagnosis of gearbox bearing. Minimum entropy deconvolution (MED) is a popular method for fault feature extraction. However, the deconvolution results are s...
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This paper develops a dynamic model for a damper-bearing-rotor system featuring a novel double layer squeeze film damper-bearing composite structure, addressing the limitations of conventional single layer dampers in ...
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The sealing-induced cross-coupling stiffness (CCS) often decreases the rotordynamic stability of turbomachinery. In our previous study, an active negative CCS control strategy applied between two bearings in the middl...
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Collisions between objects are a relatively common phenomenon in *** of collision processes can greatly contribute to solving problems such as impact-rub faults and particle *** coefficient of restitution is a critica...
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Collisions between objects are a relatively common phenomenon in *** of collision processes can greatly contribute to solving problems such as impact-rub faults and particle *** coefficient of restitution is a critical parameter in the analysis of collision *** experiments have shown that the coefficient of restitution is closely related to the plate thickness,and the smaller the plate thickness,the more inaccurate the coefficient of restitution predicted by the existing model,which seriously affects the process of collision *** remedy this shortcoming,this paper proposes a plate thickness influence factor with the ratio of sphere diameter to plate thickness as the *** plate thickness influence factor can optimize the coefficient of restitution model to effectively predict the coefficient of restitution of impacting elastoplastic spheres with finite plate ***,the validity of the new model is verified using a large amount of experimental data.
Squeeze film dampers (SFDs) have been frequently employed in aero-engines due to their excellent vibration reduction performance. However, their nonlinear characteristics make it difficult for traditional balancing me...
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—As one of the main components of hydrogen refueling stations, the diaphragm hydrogen compressor is an important equipment supporting the development of hydrogen energy in China. Currently, the diaphragm hydrogen com...
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The oil-free dry air compressor plays a crucial role in the fuel cell system, particularly in commercial buses where twin-screw air compressors have proven effective. A novel rotor profile of the twin-screw dry air co...
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Foil thrust bearings are widely used in high-speed rotating machinery due to their temperature tolerance and contamination-free operation. However, the gas film thickness of the bearing can be weakened by the runner’...
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In this study,the Mg-3Zn-0.5Zr-χNd(χ=0,0.6)alloys were subjected to final rolling treatment with large deformation of 50%.The impact of annealing temperatures on the microstructure and mechanical properties was *** ...
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In this study,the Mg-3Zn-0.5Zr-χNd(χ=0,0.6)alloys were subjected to final rolling treatment with large deformation of 50%.The impact of annealing temperatures on the microstructure and mechanical properties was *** rolled Mg-3Zn-0.5Zr-0.6Nd alloy exhibited an ultimate tensile strength of 386 MPa,a yield strength of 361 MPa,and an elongation of 7.1%.Annealing at different temperatures resulted in reduced strength and obviously increased elongation for both *** mechanical properties for the Mg-3Zn-0.5Zr-0.6Nd alloy were achieved after annealing at 200℃,with an ultimate tensile strength of 287 MPa,a yield strength of 235 MPa,and an elongation of 26.1%.The numerous deformed microstructures,twins,and precipitated phases in the rolled alloy could impede the deformation at room temperature and increase the work hardening *** annealing,a decrease in the work hardening effect and an increase in the dynamic recovery effect were obtained due to the formation of fine equiaxed grains,and the increased volume fraction of precipitated phases,which significantly improved the elongation of the ***,the addition of Nd element could enhance the annealing recrystallization rate,reduce the Schmid factor difference between basal and prismatic slip systems,facilitate multi-system slip initiation and improve the alloy plasticity.
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