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Numerical investigation in characteristics of multi-layer thrust gas foil bearing based on fluid-structure coupling field

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Chinese Journal of aeronautics 2025年

作者： Hongwei WANG Yuanwei LYU Jingyang ZHANG Qijun ZHAO Chengfeng NA Lijun CHEN College of Astronautics Nanjing University of Aeronautics and Astronautics Nanjing 210016 China College of Aeronautics Nanjing University of Aeronautics and Astronautics Nanjing 210016 China College of Mechatronics Engineering Nanjing Forestry University Nanjing 210037 China Aviation Key Laboratory of Science and Technology on Aero Electromechanical System Integration Beijing 120016 China

Rotating machinery in the aviation industry is increasingly embracing high speeds and miniaturization, and foil dynamic pressure gas bearing has great application value due to its self-lubrication and self-adaptive deformation characteristics. This study explores the interaction mechanism between micro-scale variable-sectional shearing flow with hyper-rotation speeds and a three-layer elastic foil assembly through bidirectional aero-elastic coupling in a multi-layer thrust gas foil bearing (MTGFB). The bearing capacity of the MTGFB varies non-linearly with the decrease of air film clearance, while the collaborative deformation of the three-layer elastic foil assembly can deal with different load conditions. As the load capacity increases, the enhanced dynamic pressure effect causes the top foil to evolve from a single arch to multiple arches. The hydrodynamic effects in the gas film evolve to form multiple segmented wedges with different pitch ratios, while the peak pressure of the gas film always occurs near the vaults of the top foil. As the rotational speed frequency approaches the natural frequency, the resonance of the gas film and elastic foil assembly system occurs, and a phase delay occurs between the pressure pulsation and the vibration of foils. The load capacity of the MTGFB also depends on the elastic moduli of the elastic foil assembly. Increasing the elastic modulus decreases the deformation amplitude of the top foil, whereas it increases those of the backboard and middle foil, increasing the load capacity.

关键词： thrust gas foil bearing multi-foil superposition two-way fluid-structure coupling adaptive deformation bearing capacity elastic modulus

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Modeling and Precise Position Control of Flexible Joints with Harmonic Drives

Modeling and Precise Position Control of Flexible Joints wit...

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International Conference on Electrical Machines and systems (ICEMS)

作者： Yiwei Tang Xin Sun Qi He Xi Xiao Weihua Wang Tsinghua Univerisy Beijing China Aviation key Laboratory of Science and Technology on Aerospace Power System Shaanxi Aero Electric Co. Ltd. Xi’an China Foshan (Southern China) Institute for New Materials Foshan City China

Complex torsional behaviors of harmonic drives lead to performance degradation of flexible joint servo systems, raising the need for accurate models and suited control approaches. A comprehensive model is proposed in this paper considering the friction, the nonlinear stiffness, and the kinematic error. The torsional hysteresis phenomenon of the harmonic drive is represented using Preisach model and treated inside the stiffness submodel. Identification processes for the comprehensive model based on no-load tests and stall tests are elaborated, and a control method based on feedback linearizing is also put forward. Experiment results indicate that the comprehensive model matches the measurements well, and the proposed controller shows better dynamic responses than conventional PI controllers.

关键词： Degradation PI control Friction Process control Position control Kinematics Harmonic analysis

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Propagation Characteristics of Pressure Pulsation in Hydraulic Hose

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Journal of Physics: Conference Series 2021年第1期2095卷

作者： Yuzhen Meng Lei Han Wenkui Zhao Lishan Zhang Beijing University of Posts and Telecommunications Beijing China Aviation Key Laboratory of Science and Technology on Aero Electromechanical System Integration Nanjing China

Most modern aircraft hydraulic systems use variable plunger pumps. The pulsating flow output is its inherent characteristic. The resulting pressure pulsation often causes serious damage to the energy pipeline system and endangers the lives of the occupants. This paper studies the propagation law of hydraulic oil in hydraulic hoses, fully considers the coupling vibration of hydraulic oil high-pressure fluid and flexible solids of the hose, establishes a fluid-solid coupling vibration model of hydraulic hoses, and uses ANSYS for numerical simulation to study different frequencies and pipe bending. Using ANSYS for numerical simulation to study the influence of different frequencies and pipe bending radii on the amplitude of fluid pressure pulsation, after comparative analysis, the law of fluid pressure pulsation propagation in hydraulic hoses is obtained.

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Multi-input Convolutional Neural Network Fault Diagnosis Algorithm Based on the Hydraulic Pump

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Journal of Physics: Conference Series 2021年第1期2095卷

作者： Lishan Zhang Lei Han Yuzhen Meng Wenkui Zhao Beijing University of Posts and Telecommunications Beijing China Aviation Key Laboratory of Science and Technology on Aero Electromechanical System Integration Nanjing China

Convolutional neural network used in fault diagnosis can effectively extract fault features in vibration signals. However, in the feature extraction of mechanical fault diagnosis, usually more than two feature signals including at least axial and radial vibration signals can be extracted. This paper proposes two multi-input convolutional neural network models based on the fault data of the aircraft hydraulic pump including axial and radial vibration. The first is the Independent Input Multi-input Convolutional Neural Network model. The two inputs are respectively used for convolution pooling operation with CNN, and are combined through the concatenate function before the fully connected layer, and then all frames are integrated and flattened by the flatten function. A one-dimensional array, finally enters the fully connected layer and outputs the result through the softmax function. The second is the Combined Input Multiinput Convolutional Neural Network, that is, combine two one-dimensional signals into a twodimensional signal in the input layer of the convolutional neural network and then perform convolution pooling, and finally output the result through the softmax function. The results show that the two models have good accuracy and stability, and the second one has a higher convergence and fitting efficiency than the first one.

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Study on rotor EDDY current loss of double-winding permanent magnet fault-tolerant motor for electro-hydrostatic actuator applications

Study on rotor EDDY current loss of double-winding permanent...

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CSAA/IET International Conference on Aircraft utility systems (AUS 2020)

作者： Q. Zhao Y. Hu P. Zhang L. Yang AVIC Aerospace System CO. LTD No.5 Yard Shuguang Xili Beijing China Nanjing Engineering Institute of Aircraft Systems Aviation Key Laboratory of Science and Technology on Aero Electromechanical System Integration No 33 Shuige Road Nanjing China

Rotor eddy current losses of a double-winding high-speed permanent magnet fault-tolerant motor for electro-hydrostatic actuator (EHA) applications are studied in this paper. Firstly, the rotor eddy current losses of dual-winding high-speed permanent magnet fault-tolerant motors with different winding modes are studied. Then, the rotor eddy current losses of different magnetic retaining sleeve materials such as stainless steel, titanium alloy and carbon fiber are calculated accurately. The problem of slot opening and slot segmentation in high speed permanent magnet motor with concentrated winding is analysed. Finally, a double-winding high-speed permanent magnet fault-tolerant motor prototype was fabricated to verify the analysis results.

关键词： fault tolerance eddy current losses machine windings titanium alloys finite element analysis rotors permanent magnet motors permanent magnet machines

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The Design of High-temperature Permanent Magnet Synchronous Motor based on Multi-physics Simulation

The Design of High-temperature Permanent Magnet Synchronous ...

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International Conference on Power Electronics and Motion Control (IPEMC)

作者： Yu Gao Zhenyang Hao Qiang Zhou Long Wang Yuqi Jia Wenjun Cui Yuliang Lu College of Automation Nanjing University of Aeronautics and Astronautics Nanjing China The Sixty-third Research Institute National University of Defense Technology Nanjing China Aviation Key Laboratory of Science and Technology on Aero Electromechanical System Integration AVIC Nanjing Engineering Institute of Aircraft System Nanjing China

ISBN: (数字)9781728153018

ISBN: (纸本)9781728153025

The development of power electronics technology has made it possible for all-electric combat vehicle (AECV). The high-voltage power supply system, high-temperature working environment and high power density requirements of AECV bring new challenges to the design of the permanent magnet synchronous motor (PMSM). In this paper, the electromagnetic design and thermal design of PMSM for AECV are taken as the research object. A high-speed PMSM with rated power of 1.5kW and rated speed of 18000r/min is designed. In order to accurately calculate the losses in the PMSM under the space vector pulse width modulation (SVPWM) voltage, this paper uses a multi-physics simulation method. Finally, electromagnetic simulation and thermal simulation of the motor are carried out. The results show that the motor meets the design requirements.

关键词： Space vector pulse width modulation Power system measurements Power supplies Permanent magnet motors Synchronous motors Power electronics Electromagnetics

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Reduction of Iron Loss in a V-Shaped IPM Machine for Traction Applications 22

Reduction of Iron Loss in a V-Shaped IPM Machine for Tractio...

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22nd International Conference on Electrical Machines and systems, ICEMS 2019

作者： Zhiyong, Ma Hu, Yaohua Can, Chen Navy Military Representative Office in Nanjing Fourth Representative Office of the Navy in Nanjing Nanjing211106 China Electromechanical System Integration Nanjing Engineering Institute of Aircraft Systems Aviation Key Laboratory of Science and Technology on Aero Nanjing210016 China

ISBN: (纸本)9781728133980

This paper has proposed a novelty method to reduce the iron loss of a V-shaped interior permanent magnet (IPM) machine for traction applications. By optimizing the pole-arc to pole-pitch ratios of magnets and shaping the rotor iron, the total iron losses of initial model is extremely reduced, due to the harmonics of rotor magnetomotive force are reduced. The waveforms and harmonics of air gap flux density and flux density of stator core are studied. The core loss and core loss density of three IPM motors are analyzed and compared. The efficiency of the optimized V-shaped IPM machine can be improved under high speed condition by the reduction of iron loss. © 2019 IEEE.

关键词： Iron

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Electromagnetic performance analysis of external rotor IPM machine for aircraft applications

Electromagnetic performance analysis of external rotor IPM m...

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CSAA/IET International Conference on Aircraft utility systems (AUS 2020)

作者： X. Huang Y. Hu P. Zhang Y. Zhang Fourth Representative Office of the Navy Navy Military Representative Office in Nanjing No 33 Shuige Raod Nanjing China Nanjing Engineering Institute of Aircraft Systems Aviation Key Laboratory of Science and Technology on Aero Electromechanical System Integration No 33 Shuige Raod Nanjing China

This paper has proposed an external rotor fractional slot concentrated winding (FSCW) interior permanent magnet (IPM) machine for aircraft traction applications. The electromagnet performance at no-load condition such as air-gap flux density, flux linkage distribution, electromotive force (EMF), and cogging torque are studied. The electromagnet performance at rated-load condition such as average torque, torque ripple, and iron losses are investigated. It can be found that, the advantages of the external rotor IPM machine are high torque density, high power density, and simple structure.

关键词： machine windings electric potential permanent magnet machines torque rotors finite element analysis stators permanent magnet motors magnetic flux traction

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Study on load torque disturbance observation and compensation in electromechanical actuator

Study on load torque disturbance observation and compensatio...

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CSAA/IET International Conference on Aircraft utility systems, AUS 2018

作者： Xi, Xiao Xia, Wu Liu, Chunqiang Wang, Yongqing Aviation Key Laboratory of Science and Technology on Aero Electromechanical System Integration Nanjing China Xian China

ISBN: (纸本)9781785617911

Compared with the traditional servo valve controlled hydraulic actuator(SHA), the electromechanical actuator(EMA) has the advantages of simple structure and easy maintenance. Aiming at the load torque ripple caused by the parameter perturbation and the random change of the load in the dynamic control of the electromechanical actuator, the load torque observation method of the electromechanical actuator is carried out. According to the mathematical model of electromechanical actuator, the expression of load torque estimation is deduced, and an online estimation method is designed to observe load torque in operation process and improve torque ripple caused by parameter perturbation. © 2018 IET Conference Publications. All rights reserved.

关键词： Electromechanical actuators

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A study on electromagnet attraction characteristics based on Maxwell

A study on electromagnet attraction characteristics based on...

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CSAA/IET International Conference on Aircraft utility systems, AUS 2018

作者： Yang, Le Aviation Key Laboratory of Science and Technology on Aero Electromechanical System Integration AVIC NEIAS Nanjing China

ISBN: (纸本)9781785617911

The structure and working principles of airborne electromagnets were introduced and magnetic field analysis and electromagnetic attraction calculation were completed with Maxwell electromagnetic simulation software. By magnetostatic field analysis, the distribution diagrams of magnetic lines of force and magnetic induction intensity were obtained;by electromagnet attraction analysis, the electromagnet attraction was calculated and the impacts of materials, air gap and excitation on electromagnet attraction were examined, thus p roviding va luab le referen ce for electroma gn et op timi zation. © 2018 IET Conference Publications. All rights reserved.

关键词： Electromagnets

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