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2024 CSAA/IET International Conference on Aircraft Utility Systems, AUS 2024

作者： Shen, Haiming Hao, Meiqing Ren, Jiawei An, Zhixuan Long, Zhengwei Key Laboratory of Civil Aircraft Airworthiness Technology Civil Aviation University of China China College of Safety Science and Engineering Civil Aviation University of China Tianjin China School of Environmental Science and Engineering Tianjin University Tianjin China

This study examines the effects of different ventilation environments in the cockpit on the physiological state of pilots by using the human heart rate variability (HRV) indexes. The experiment involved collecting HRV data from pilots in the cockpit under three different ventilation conditions using the HEXOSKIN physiological monitoring vest. The results showed significant differences in Parasympathetic Nervous System index (PNS), Sympathetic Nervous System index (SNS), Mean Heart Rate (HR), and Standard Deviation of NN intervals (SDNN) indexes among the different ventilation schemes. By comparing the changes in HRV indexes under the three different ventilation conditions, the optimal cockpit ventilation scheme was determined. © The Institution of Engineering & technology 2024.

关键词： Cockpits (aircraft)

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The dielectric behavior and efficient microwave absorption of doped nanoscale LaMnO_(3)at elevated temperature

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Nano Research 2022年第8期15卷 7731-7741页

作者： Zhigang Mu Guoke Wei Hang Zhang Lu Gao Yue Zhao Shaolong Tang Guangbin Ji College of Materials Science and Technology Nanjing University of Aeronautics and AstronauticsNanjing 210016China Aviation Key Laboratory of Science and Technology on Advanced Surface Engineering AVIC Manufacturing Technology InstituteBeijing 100024China National Laboratory of Solid State Microstructures Nanjing UniversityNanjing 210093China

LaMnO_(3)perovskite has great potential in microwave absorption at high temperature due to its complex doping effect and super *** current research mainly focuses on the doping ratio regulation,while the mechanism of doping effect at high temperature is still lack of sufficient *** this work,La1−xSrxMn1−yFeyO_(3)(LaMnO_(3),La_(0.7)Sr_(0.3)MnO_(3),and La_(0.7)Sr_(0.3)Mn_(0.8)Fe_(0.2)O_(3))nanostructures with different doping sites were successfully prepared by the solid phase reaction ***,the high temperature dielectric test samples were obtained by mixing with cordierite(2MgO·2Al_(2)O_(3)·5SiO_(2)(MAS)).The results showed that the temperature dependence of Mn ion spin state had a significant impact on the high temperature dielectric behavior of La_(1−x)Sr_(x)Mn_(1−y)FeyO_(3).Particularly,when the thickness is only 1.9 mm,La_(0.7)Sr_(0.3)Mn_(0.8)Fe_(0.2)O_(3)/MAS can achieve the widest bandwidth of 4.2 GHz covered the entire X-band(8.2–12.4 GHz)and a minimum reflection loss(RL)value of−17.99 dB at 500℃.In order to improve the operating temperature of La_(0.7)Sr_(0.3)Mn_(0.8)Fe_(0.2)O_(3)/MAS,a cellular array structure was designed by using computer simulation technology(CST)software to introduce magnetic *** the outer length of the hexagon is 1 mm and the coating thickness is 1.9 mm,the widest bandwidth covers the X-band and the minimum RL value is−15.35 dB at 800℃.Therefore,La_(0.7)Sr_(0.3)Mn_(0.8)Fe_(0.2)O_(3)has a great prospect as an efficient high temperature microwave absorber.

关键词： microwave absorption doping perovskite high temperature dielectric behavior

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Characteristic of fluoroether gum via non-linear rheological approaches

Characteristic of fluoroether gum via non-linear rheological...

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2024 International Conference on Materials Physics and Composites, ICMPC 2024

作者： Song, Ronghao Yang, Rui Wang, Chen Su, Zhengtao Aviation Key Laboratory of Science and Technology on Materials and Application Research for Vibration and Noise Reduction AECC Beijing Institute of Aeronautical Materials Beijing100095 China

Large amplitude oscillatory shear (LAOS) tests were conducted on four types of fluoroether elastomer gum, namely VPL-85540, VPL-75545, VPL-65455, and VPL-55540 in order to study their molecular weight, chain structure, and branching degree from the perspective of rubber rheology. For the setting of shear rate in varied LAOS measurements, frequency and angular velocity controlling modes were attempted and compared. Non-linear rheological parameters showed that VPL-65455 possessed significant polymeric branching characteristics. VPL-55540 possessed the lowest molecular weight, and VPL-75545 was detected with higher long-pendant monomer content in its polymer chain. Rheological properties concluded from the analysis of two shear rate controlling modes of LAOS tests exhibited great consistency, which confirmed the reliability of LAOS tests in the characterization of fluoroether gum. © 2024 Institute of Physics Publishing. All rights reserved.

关键词： Shear flow

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Cooperative sliding-mode guidance law for active protection 41

Cooperative sliding-mode guidance law for active protection

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第41届中国控制会议

作者： HUA Wen-hua ZHANG Jin-peng China Airborne Missile Academy Aviation Key Laboratory of Science and Technology on Airborne Guided Weapons

ISBN: (数字)9789887581536

ISBN: (纸本)9781665482561

As compared with the attacking missile,the aircraft had the disadvantages of flight speed and *** improve the survivability,the aircraft could launch a defending missile to intercept the attacker and correspondingly,a cooperative guidance law of defending missile was presented based on adaptive sliding-mode *** guidance law was a kind of line of sight(LoS) guidance approach in essence,which guided the defending missile to locate inside the LoS between the aircraft and the attacking missile for active *** simulations show that this guidance law has the advantages of maneuvering performance and intercepting performance compared to the proportional navigation because of the cooperation with the aircraft and has strong robustness to the speed variations of the three bodies and the maneuver of the attacking missile.

关键词： guidance law adaptive sliding-mode control cooperation guidance line of sight guidance

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A new method to identify rotor–stator rubbing positions based on intrinsic time scale decomposition

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Noise and Vibration Worldwide 2022年第3期53卷 120-132页

作者： Yu, Mingyue Chen, Wangying Wang, Jinglin Cong, Haonan Shenyang Aerospace University Shenyang China Aviation Key Laboratory of Science and Technology on Fault Diagnosis and Health Management Shanghai201601 China

To effectively identify the rotor–stator rubbing positions in aero-engine, the paper has proposed the combination of intrinsic time-scale decomposition (ITD) and classification algorithm. Regarding that with larger noise component in proper rotation component (PRC) signals after ITD, it will be more difficult to extract the characteristic information of rubbing faults, the PRC correspondings to the largest noise was eliminated. Meanwhile, signals were reconstructed based on residual proper rotation components, and positions of rubbing faults were identified according to the reconstructed signal. As rubbing extent and other factors cannot be completely the same in each rubbing, energy of reconstructed signal has been normalized to reduce the difference. Normalized energy indexes were inputted into classification algorithm as feature vectors to identify the positions of rubbing faults. To identify the superiority of approach, a comparison has been made between the proposed approach and the method of directly extracting normalized energy indexes of acceleration signals. The result of comparison shows that the two methods both work well in the identification rate of training and test samples;as for the identification rate for an unknown sample, the proposed method is superior to the other, with identification rate increasing by 17% and 9.4%. © The Author(s) 2021.

关键词： Signal reconstruction

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A Grey Wolf Optimizer Variant with Weighted-leader Strategy 24

A Grey Wolf Optimizer Variant with Weighted-leader Strategy

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3rd International Conference on Signal Processing, Computer Networks and Communications, SPCNC 2024

作者： Liang, Yajun Yan, Su Ma, Qian Huang, Shunlun Liu, Xin China Aerodynamics Research & Development Center Sichuan Mianyang China Science and Technology on Complex Aviation Systems Simulation Laboratory Beijing China State Key Laboratory of Air Traffic Management System Beijing China Beijing Aviation Meteorological Institute Beijing China

ISBN: (纸本)9798400710834

To enhance the convergence capability of grey wolf optimizer (GWO), this research investigates an evolved GWO using weighted-leader strategy (WLS), namely WLSGWO. The key issue of WLS is realizing the adaptive adjustment of position weighting according to the control parameters, thus well overcoming the drawback of premature convergence in the basic GWO. The newly developed method’s performance is assessed through experiments conducted on a standardized test suite. Additionally, comparisons are made by utilizing GWO alongside other advanced optimization techniques. The results of non-parametric studies validate the outperformance of the WLSGWO, thus proving the efficiency of the proposed strategy. © 2024 Copyright held by the owner/author(s).

关键词： Swarm intelligence

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A radar-infrared compatible broadband absorbing surface:Design and analysis

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Chinese Physics B 2021年第7期30卷 605-612页

作者： Qing-Tao Yu Yuan-Song Zeng Guo-Jia Ma Aviation Key Laboratory of Science and Technology on Advanced Surface Engineering AVIC Manufacturing Technology InstituteBeijing 100024China

A radar-infrared compatible stealth surface is designed and *** modifying the radar absorbing material(RAM),the design can theoretically achieve radar-infrared compatibility and broadband radar absorption through surface patterns and structures.A transmission-line-based model(TLM)is developed to analyze the radar absorbing performance of the *** of the structure geometries is conducted aiming to maximize the-10 d B absorption bandwidth in 2–18 *** with optimized structure geometries exhibits a superior absorption bandwidth,more than twice the bandwidth of the original 1.5 mm RAM slab,while maintaining a relatively low infrared emissivity.

关键词： stealth infrared-radar compatible broadband absorbing patterned surface

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Rubik’s cube as in-situ programmable matter and a reconfigurable mechanical metamaterial

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science China(Technological sciences) 2024年第10期67卷 3221-3234页

作者： ZHU ShaoWei CHEN Huan YANG XiaoQiang TAN Li JIN Shuai CHEN LiMing LIU Tao TAN XiaoJun WANG LianChao WANG Bing MUAMER Kadic State Key Laboratory of Coal Mine Disaster Dynamics and Control Chongqing UniversityChongqing 400030China College of Aerospace Engineering Chongqing UniversityChongqing 400030China School of Civil Aviation Northwestern Polytechnical UniversityXi’an 710129China National Key Laboratory of Science and Technology on Advanced Composites in Special Environments Harbin Institute of TechnologyHarbin 150080China Institut FEMTO-ST CNRS UMR 6174University BourgogneFranche-ComtBesan¸con 25000France

As part of the 4th industrial revolution,programmable mechanical metamaterials exhibit great application potential in flexible robotics,vibration control,and impact ***,maintaining a programmed state without sustaining the external stimulus is often challenging and leads to additional energy *** by Rubik’s cube,we design and study an in-situ programmable and distribution-reconfigurable mechanical metamaterial(IPDR-MM).A matrix model is developed to model IPDR-MMs and describe their morphological *** on this model,the reinforcement learning method is employed to find the pathways for morphological *** find that IPDR-MMs have controllable stiffness across several orders of magnitude and a wide range of adjustable anisotropies through morphology ***,because of the independence of the directions of morphology transformation and bearing,IPDR-MMs exhibit good stability in bearing and can readily achieve high *** Rubik’s cube-inspired design concept is also instructive for other deformable structures and metamaterials,and the current version of the proposal should be sufficiently illustrative to attract and broaden interdisciplinary interests.

关键词： mechanical metamaterials in-situ programmable distribution-reconfigurable Rubik’s cube controllable stiffness and anisotropy

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Characteristics Research of Multi-scale Wind Model by the Space and Time 7th

Characteristics Research of Multi-scale Wind Model by the Sp...

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7th China Aeronautical science and technology Conference, CASTC 2024

作者： Fang, Zijun Zhang, Ge AVIC Aerodynamics Research Institute Shenyang110034 China Aviation Key Laboratory of Science and Technology on Aerodynamics of High Speed and High Reynolds Number Shenyang110034 China

ISBN: (纸本)9789819797646

aviation’s application scope gradually expands, increasing flight requirements tailored for low-altitude environments. In such environments, the occurrence of random gusts affects both flight stability and safety. Additionally, the scale and magnitude of these random gusts significantly influence aircraft structural design and handling performance evaluation. A novel method is proposed based on the direct computation of gust magnitude at any location using correlation spectra of gusts at different scales and modelling the scale correlation of gusts at various altitudes. This method presents spectral and discrete models for multi-scale wind superposition, derives confidence calculation functions for wind model correlation indicators, and validates them through existing measurement data. The validation results indicate that the magnitude and scale of multi-scale wind superposition models can scale at any location with any desired level of confidence. © Chinese Society of Aeronautics and Astronautics 2025.

关键词： Structural design

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An architecture decomposition method of pneumatic catapult system based on OPM and DSM

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Chinese Journal of Aeronautics 2023年第8期36卷 168-181页

作者： Lu GAN Gang YANG Xianhui LI Enze ZHU Hu CHEN Xiaohui WEI State Key Laboratory of Mechanics and Control of Aerospace Structures Nanjing University of Aeronautics and AstronauticsNanjing 210016China Key Laboratory of Fundamental Science for National Defense-Advanced Design Technology of Flight Vehicle Nanjing University of Aeronautics and AstronauticsNanjing 210016China College of General Aviation and Flight Nanjing University of Aeronautics and AstronauticsNanjing 210016China

The architecture strategy of the Unmanned Aerial Vehicle(UAV)pneumatic launch system should continue to evolve to adapt to complex and variable operating *** representation,decomposition perspective,and cluster analysis play a vital role in the early phase of system architecture *** order for the system to emerge anticipated and desirable intrinsic functional properties,an architecture decomposition method based on the ObjectProcess Methodology(OPM)and Design Structure Matrix(DSM)is put forward in this *** OPM is proposed to model the UAV launch process formally,and the matrix representation of the architecture of the pneumatic launch system is *** the extension of the definition and operations of DSM,with the Idicula-Gutierrez-Thebeau Algorithm plus(IGTA+)clustering algorithm,the transformation of the pneumatic launch system architecture from process decomposition to function decomposition is demonstrated in this *** analysis shows that the architecture decomposition of the pneumatic launch system meets the functional requirements of stakeholders.

关键词： Architecture decomposition Cluster analysis Design structure matrix Object-process methodology Pneumatic catapult system

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