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SSRN 2024年

作者： He, Zhenzong Zuo, Min Liang, Shuang Mao, Junkui College of Energy and Power Engineering Nanjing University of Aeronautics and Astronautics Nanjing210016 China Collaborative Innovation Center for Advanced Aero-Engine Beijing100191 China Aviation Key Laboratory of Science and Technology on Aero Electromechanical System Integration Nanjing211106 China

This study addresses the thermal management of the turbine disc cavity system (TDCS) by combining the feed-forward backward propagation neural network (FFBPNN) with the non-dominated sorting genetic algorithm II (NSGA II). First, the heat transfer analysis of the TDCS is carried out using the 1D fluid network method and the 2D finite element method. The impact of different cooling air inlet conditions on the heat transfer performance of the TDCS is investigated. The results show that changing the inlet pressure and temperature significantly affects the heat transfer performance of the TDCS, and the TDCS temperature field can be regulated by the inlet parameters. Then, the prediction model based on the FFBPNN is established to predict the heat transfer performance of the TDCS, and satisfactory result is obtained with mean relative error lower than 1.5% and a coefficient of determination higher than 0.998. Finally, the NSGA II is employed to optimize the cool air inlet condition to achieve thermal management of the TDCS. The Pareto solution set and the optimal solution are obtained. The results indicate that the most comprehensive improvement in the heat transfer performance of the TDCS can be achieved by the present technology. © 2024, The Authors. All rights reserved.

关键词： Temperature control

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A Decentralized SoC Balancing Technique for Precharging Series Energy Storage systems 48

A Decentralized SoC Balancing Technique for Precharging Seri...

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48th Annual Conference of the IEEE Industrial Electronics Society, IECON 2022

作者： Li, Yao Wu, Donghua Qi, Yang Li, Weilin Northwestern Polytechnical University School of Automation Xi'an China Shaanxi Aero Electric Co. Ltd Aviation Key Laboratory of Science and Technology on Aerospace Power System Xi'an China

ISBN: (数字)9781665480253

ISBN: (纸本)9781665480253

Energy storage systems (ESSs) are widely installed in the present power system. When multiple ESSs are connected in series, proper power sharing is needed to avoid the unbalance SoC issue: some ESSs are not fully charged while others have been overcharged. Due to geographical restriction, there is usually no communication link between different ESSs. In this case, each ESS only knows its local information, such as the state of charge (SoC), output current, and voltage. It is therefore more challenging to achieve the ESS SoC balancing during the pre-charging state. To address this issue, a decentralized SoC balancing control based on complex virtual impedance has been proposed in this paper. The proposed method controls the ESS as a virtual complex impedance, whose impedance angle is correlated with the real-time SoC value. Through this effort, the active power of ESS can be dynamically regulated during the entire pre-charging process to autonomously realize SoC balancing. Finally, hardware-in-loop (HIL) simulation results of a series ESS system are provided for verification. © 2022 IEEE.

关键词： Energy storage

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A Health Assessment Method of Avionics Equipment 6th

A Health Assessment Method of Avionics Equipment

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6th China aeronautical science and technology Conference, CASTC 2023

作者： Huang, Bing Zhou, Jing Cao, Liang Wang, Jinglin Shan, Tianmin Liu, Ying Yao, Xiaohan Luo, Zexi Jiang, Fan Li, Qinyang Aviation Key Laboratory of Science and Technology on Fault Diagnosis and Health Management Shanghai201601 China AVIC United Technology Center for Basic Research on Aircraft System Fault Diagnosis and Health Management Shanghai201601 China AVIC Shanghai Aero Measurement and Controlling Research Institute Shanghai201601 China Company Ltd. Hanzhong723215 China

ISBN: (纸本)9789819988600

With the popularization of aircraft digitization, PHM (prognosis and health management) of avionics equipment is becoming increasingly important. Due to the difficulty in collecting performance parameters for avionics equipment, we propose a new method, which achieves component-level health assessment based on fault risk. In response to the issue of assessment weight dilution in the system, considering the impact of serial and parallel structures on system functionality, an improved health assessment method based on reliability logic was proposed to achieve system-level health assessment. And then, based on the above, we integrated a health assessment algorithm for avionics equipment. Through example Analysis, the methodology proposed in this paper can effectively evaluate the health status of the avionics equipment population. The analytical health calculation method proposed in this article has a fast calculation speed, which is easily deployed onboard health assessment systems and enhances the health management capabilities of avionics equipment. © 2024, Chinese Society of aeronautics and Astronautics.

关键词： Risk assessment

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Application of WSGSA Model in Predicting Temperature and Soot in C_(2)H_(4)/Air Turbulent Diffusion Flame

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Transactions of Nanjing University of aeronautics and Astronautics 2022年第4期39卷 482-492页

作者： HE Zhenzong ZHU Ruihan DONG Chuanhui MAO Junkui FU Yao College of Energy and Power Engineering Nanjing University of Aeronautics and AstronauticsNanjing 210016P.R.China Aviation Key Laboratory of Science and Technology on Aero Electromechanical System Integration Nanjing 211106P.R.China

Soot,a product of insufficient combustion,is usually in the form of aggregate. The multi-scattering of soot fractal aggregates has been proved to play an important role in studying the soot radiative properties,which is rarely considered in predicting the radiative heat transfer in combustion flame. In the present study,based on the weighted sum of gray soot fractal aggregate(WSGSA) model,which is used to predict the temperature field and soot aggregates in turbulent diffusion flame,the flame temperature distribution and soot volume fraction distribution under the conditions of the model without considering radiation,the default radiation model in Fluent software and the WSGSA model are calculated respectively. The results show that the flame temperature will be seriously overestimated without considering radiation and the maximum relative discrepancy of flame centerline temperature is about 64.5%. The accuracy will be improved by the default radiation model in the Fluent software,but the flame temperature is still overestimated and the maximum relative discrepancy of flame centerline temperature is about 42.1%. However,more satisfactory results can be obtained by the WSGSA model,and the maximum relative discrepancy of flame centerline temperature is no more than 15.3%. Similar conclusions can also be obtained in studying the temperature distribution along different flame heights. Moreover,the soot volume fraction can be predicted more accurately with the application of the WSGSA model. Both without considering radiation and using the default radiation model in the Fluent software will result in the underestimating of soot volume fraction. All the results reveal that the WSGSA model can be used to predict the temperature and soot aggregates in the CH/air turbulent diffusion flame.

关键词： radiative heat transfer WSGSA model soot radiation turbulent diffusion flame soot aggregate

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Research on Fault-tolerant Operation of Fault-tolerant Permanent Magnet Motor Based on Four-switch Two-phase Fault-tolerant Topology

Research on Fault-tolerant Operation of Fault-tolerant Perma...

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International Conference on Power Electronics systems and Applications (ICPESA)

作者： Xuefeng Jiang Siyuan Wang Kaiwen Wang Hongbo Liu Zhijian Wei Zhenmao Han School of Automation Nanjing University of Science and Technology Nanjing China Aviation Key Laboratory of Science and Technology on Aero Electromechanical System Integration Nanjing China

ISBN: (纸本)9781665486699

Multi - electric aircraft have attracted more and more attention at domestic and abroad in recent years. As the core component of the more-electric aircraft hydraulic system, the partial energy electric pump determines the performance of the aircraft actuating device. However, for the partial energy pump motor system, electrical faults exist objectively, and after the faults, the system will not run stably. In this paper, a fault-tolerant permanent magnet motor(FTPMM) drive system based on four-switch two-phase (FSTP) fault-toleranttopology is proposed. The principle of fault-tolerant control(FTC) before and after the fault is analyzed by means of constant magnetomotive force, and the FTC strategy for winding open-circuit(OC) and short-circuit(SC) faults of the electric drive system is proposed. Through theoretical research, simulation analysis and verification, It is verified that the FTPMM drive system based on the four-switch two-phase fault-tolerant topology can not only perform FTC for winding OC faults, but also perform FTC for winding SC faults. This improves the reliability of the avionics transmission system.

关键词： Fault tolerance Analytical models Torque Magnetic cores Fault tolerant systems Windings aerospace electronics

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Learning to Update Engine Models with Deep Reinforcement Learning

Learning to Update Engine Models with Deep Reinforcement Lea...

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International Symposium on Autonomous systems (ISAS)

作者： RuoYan Yu Bei Li SuMu Shi Cong Peng YuNan Zhou XiangYu Du School of Automation Nanjing University of Aeronautics and Astronautics Nanjing China Aviation Key Laboratory of Science and Technology on Aero Electromechanical System Integration Nanjing Engineering Institute of Aircraft Systems Nanjing China

Model updating can reduce the reality gap between the digital space and physical space, which is essential for accurately building digital models of aviation equipment. However, with data requirements and the complexity of application environments continue to increase, traditional update techniques show great limitations. The main reason is that traditional update technologies are limited by computational efficiency, resulting in the inability to balance accuracy and real-time. In this work, we propose a model update method based on reinforcement learning to infer model parameters. The proposed method does not require any ground truth parameters. Experimental results on the twin-rotor turbofan engine model verify the superiority of the proposed method compared with other state-of-the-art methods.

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Numerical And Experimental Investigations On Cavitation Characteristics Of Inducer And Impeller Combination Fuel Pumps

Numerical And Experimental Investigations On Cavitation Char...

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2022 CSAA/IET International Conference on Aircraft utility systems, AUS 2022

作者： Tian, Qilong Lin, Chengwei Hu, Rongxia Ya, Chen Xu, Sanshu Aviation Key Laboratory of Science and Technology on Aero Electromechanical System Integration Nanjing211106 China Nanjing Engineering Institute of Aircraft Systems AVIC Nanjing211106 China The Third Military Representative Office of the Shanghai Bureau of the Air Force Equipment Department in Nanjing Nanjing211106 China

ISBN: (数字)9781839537769

ISBN: (纸本)9781839537769

The aviation fuel pump is a significant accessory for aircraft fuel system. Cavitation resistance is very important for aviation fuel pumps. However, most of the current optimization work for centrifugal pumps only focuses on hydraulic efficiency, which may lead to poor cavitation performance. Therefore, it is necessary to explore effective solutions to improve the cavitation performance of the pump without reducing the efficiency of the pump. To enhance the anti-cavitation capability of the pump and reduce hydraulic loss, the paper try to combine the inducer and impeller. Simulations and external characteristics experiments are carried out. Static pressure and the vapor volume fraction distributions on the inducer and the impeller of the pump under various operation conditions are obtained. At the same time, the curves for the drops of the head coefficients obtained from experiments and calculations are also quantitatively compared, which shows that the numerical simulation of the cavitation performance of the fuel pump is in good agreement with the experimental results. The maximum error of both simulation and experiment is less than 6%, which is within the allowable error range. It indicates that the numerical calculation method adopted can better predict the cavitation performance of the fuel pump. © 2022 IET Conference Proceedings. All rights reserved.

关键词： Cavitation

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Simulation Analysis of Electromagnetic Output Force of Linear Motor with Single Magnetic Steel or Dual Magnetic Steel

Simulation Analysis of Electromagnetic Output Force of Linea...

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World Conference on Mechanical Engineering and Intelligent Manufacturing (WCMEIM)

作者： Yu–kun Zhou Hai–ling Qiu Nanjing Engineering Institute of Aircraft Systems Aviation Key Laboratory of Science and Technology on Aero Electromechanical System Integration Nanjing Jiangsu China

ISBN: (纸本)9781665473705

Taking the dual magnetic steel force motor used in a certain type of direct drive valve as the research object, the corresponding single magnetic steel force motor is derived according to its structure. Due to the similar structure of the single magnetic steel force motor and the dual magnetic steel force motor, the Ansoft electromagnetic simulation software can be used under the same conditions of armature parameters, air gap width, number of coil turns, and parts materials, etc. By analyzing the difference between the output force of single magnetic and dual magnetic force motors, the characteristics of the electromagnetic output force of both are determined.

关键词： Analytical models Atmospheric modeling Force Valves Magnetic analysis Structural engineering Steel

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Numerical Analysis on the Performance and Axial Force Characteristics of Low Specific Speed and High Head aviation Fuel Pump

Numerical Analysis on the Performance and Axial Force Charac...

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2022 CSAA/IET International Conference on Aircraft utility systems, AUS 2022

作者： Han, Zhenrong Tian, Qilong Fan, Hongxing Chen, Ya Cui, Zongtai Aviation Key Laboratory of Science and Technology on Aero Electromechanical System Integration Nanjing211106 China Nanjing Engineering Institute of Aircraft Systems AVIC Nanjing211106 China The Third Military Representative Office of the Shanghai Bureau of the Air Force Equipment Department in Nanjing Nanjing211106 China

ISBN: (数字)9781839537769

ISBN: (纸本)9781839537769

The research on the axial force is an important issue for the fuel pump. For the aviation fuel pumps with low specific speed and high head, due to the larger projection area of its impeller cover, and the higher fluid pressure in the pump cavity are more likely to cause an excellent axial force. The performance and axial force characteristics of low specific speed and high head aviation fuel pump was numerically simulated and analyzed. The results of the study showed that the main parts of the fuel pump that generate axial force are the front cover, the rear cover, the impeller and the inducer. The axial force can be reduced by increasing the diameter of the rear cover labyrinth ring and adding the balancing holes. Thus, reducing the loss of the fuel pump and improving the hydraulic efficiency, and the problem of excessively high temperature of the fluid in the pump is solved. This study is helpful to improve the operation stability of fuel pump, and provide reference for subsequent research. © 2022 IET Conference Proceedings. All rights reserved.

关键词： Fuels

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A Method for Reconstructing the Shape of Wing Panels Based on Fiber Optic Sensors and Tomographic Imaging Principles

A Method for Reconstructing the Shape of Wing Panels Based o...

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Prognostics and system Health Management Conference (PHM-Qingdao)

作者： Jun Zhan Jie Zeng Chao Xiang Jinpeng Cui Cheng Zeng Linfeng Zhu Mingyu Lu State Key Laboratory of Mechanics and Control for Aerospace Structures Nanjing University of Aeronautics and Astronautics Nanjing China Aviation key laboratory of science and technology on aero electromechanical system integration Nanjing engineering institute of aircraft system jincheng AVIC Nanjing China Changping District Xiaotangshan Future Science and Technology City COMAC Beijing Aircraft Technology Research Institute Beijing China

ISBN: (数字)9798350354010

ISBN: (纸本)9798350354027

The aircraft wing structure shape reconstruction method based on discrete strain information not only provides data support for the digital collaborative health monitoring and prediction technology of wing structure but also helps to improve the aerodynamic shape and flight quality of the aircraft, achieve structural stealth, and enhance the pointing accuracy of the on-board conformal antenna. As result, a wing skin panel shape reconstruction method based on the principle of tomographic imaging and strain information perception is proposed. According to the idea of tomographic imaging, a “non-intrusive” layout form that only requires sensors to be arranged on the periphery of the monitoring area is designed, breaking through the limitation that sensors can not be arranged in the monitoring area under special working conditions. A method for constructing the deflection shape function of the wing skin panel based on the concept of synthetic curvature is proposed, solving the problem of error accumulation and elimination of deformation inversion at non-monitoring points of the measured structure caused by the uncertainty of the limited discrete layout of sensors and the choice of interpolation fitting method. On this basis, a model deformation monitoring and inversion system for wing skin panel based on fiber optic grating sensors is constructed. The experimental results show that under the single-end fixed bending and torsion working condition, the average relative error of the panel model shape reconstruction is 4.17%. Under the double-end fixed double-concentrated load working condition, the average relative error of the shape reconstruction is 8.07%. The wing deformation distribution information reconstructed by the method proposed in this paper can be mapped onto the virtual twin model of the wing, providing technical support for the safety assessment, early warning, and on-condition maintenance of the entire service life of key structures of the aircraft.

关键词： Employee welfare Shape Deformation Layout Imaging Sensors Aircraft Monitoring Image reconstruction Strain

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