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Study on the Impact of Novel Flow Channel Structures With Spherical Obstacles on SOFC Performance

Kung Cheng Je Wu Li Hsueh Pao/Journal of Engineering Thermophysics 2025年第4期46卷 1343-1346页

作者： Zhao, Weiwei He, Zhenzong Mao, Junkui Liang, Fengli Wang, Zaixing Fu, Yao Nanjing University of Aeronautics and Astronautics College of Energy and Power Engineering 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

To enhance the performance of Solid Oxide Fuel Cells (SOFCs), a new flow channel with spherical obstacles is proposed and compared with traditional designs. It is concluded that compared with the basic straight channel, the current density of SOFC with rectangular baffles and SOFC with spherical obstacles increases by 6.42% and 7.14%, and the total pressure drop increases by 3.62 times and 2.16 times, respectively. It is thus evident that the new SOFC design proposed in this paper can be used for better overall performance. © 2025 science Press. All rights reserved.

关键词： Numerical models

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Measurement-based Path Loss Prediction and Analysis in Water Scenarios

Measurement-based Path Loss Prediction and Analysis in Water...

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IEEE International Conference on Computational Electromagnetics (ICCEM)

作者： Hanpeng Li Xiaomin Chen Hangang Li Jian Ma Xuchao Ye Lixin Song Taotao Zhang Weizhi Zhong Qiuming Zhu College of Electronic and Information Engineering Nanjing University of Aeronautics and Astronautics Nanjing China Aviation Key Laboratory of Science and Technology on Aero Electromechanical System Integration Nanjing China State Key Laboratory of Complex Electromagnetic Environment Effects on Electronics and Information System Luoyang China

ISBN: (数字)9798350383317

ISBN: (纸本)9798350383324

Unmanned aerial vehicles (UAVs) have enabled the unmanned management of water areas. Path loss (PL) serves as a critical factor that affects the UAV communication quality. In this work, a PL model for UAV channel in water scenarios is proposed, aiming to explore the multidimensional relationship between transceiver distance, carrier frequency, UAV height, and PL by constructing an Artificial Neural Network (ANN). Moreover, channel measurements are conducted in a river area, and the obtained data are analyzed using the proposed ANN model as well as the close-in (CI) model. The analysis results demonstrates that the PL increases initially and then declines as the UAV height increases. The proposed ANN model has higher prediction accuracy than the classic empirical model, and can achieve precise prediction of the PL in water scenarios.

关键词： Analytical models Accuracy Computational modeling Artificial neural networks Predictive models Autonomous aerial vehicles Data models

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Instability threshold analysis and optimization of a rotor system considering the Alford force 57

Instability threshold analysis and optimization of a rotor s...

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57th International Conference on Vibroengineering

作者： Fu, Yao Wang, Fei AVIC Jincheng Nanjing Engineering Institute of Aircraft Systems Nanjing211106 China China Aviation Key Laboratory of Science and Technology on Aero Electromechanical System Integration Nanjing211106 China College of Aircraft Engineering Nanchang Hangkong University Nanchang China

Under certain circumstances, the Alford force might induce instability of the rotor system. The mechanism and influence factors of the Alford force induced instability were analyzed with the Jeffcott rotor. Then a method for calculating the instability threshold was proposed. Finally, the optimization model of a high-speed micro-turbojet engine was established to optimize the instability threshold. The results show that the anisotropy of support stiffness and the damping ratio can both improve the threshold of instability. The instability threshold can be greatly improved by optimizing bearing stiffness and diameter of the rotor system. Copyright © 2022 Yao Fu, et al.

关键词： Stability

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Channel Fading Emulation for Highly Dynamic Communication Scenarios

Channel Fading Emulation for Highly Dynamic Communication Sc...

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IEEE International Conference on Computational Electromagnetics (ICCEM)

作者： Sheng Fang Ling Yang Jian Ma Yuetian Xie Maozhong Song Lixin Song Boyu Hua Qiuming Zhu Dan Shi College of Electronic and Information Engineering Nanjing University of Aeronautics and Astronautics Nanjing China Aviation Key Laboratory of Science and Technology on Aero Electromechanical System Integration Nanjing China Electronic Science and Technology Beijing University of Posts & Telecommunications Beijing China

ISBN: (数字)9798350383317

ISBN: (纸本)9798350383324

Highly dynamic communication terminals have a crucial role in future communication networks. In this article, a channel emulator is designed and implemented on a Field Programmable Gate Array (FPGA) platform to generate channel fading for highly dynamic communication. To reproduce the fast time-varying channel characteristics, a hardware time-evolution method of channel parameters based on scenario-dependent information is proposed. The measurement results indicate that the proposed channel emulator achieves continuity in the time evolution of channel parameters, and the Doppler power spectral density of the emulated channel match the theoretical results, validating the effectiveness of the emulator.

关键词： Fading channels Accuracy Power measurement Emulation Time-varying channels Hardware Time measurement

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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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