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2023 2nd International Conference on Aerospace and Control Engineering, ICoACE 2023

作者： Wang, Bingqian Wang, Zhe Sun, Zhi Hou, Bin College of Civil Aviation Nanjing University of Aeronautics and Astronautics Nanjing211106 China Key Laboratory of Aircraft Environment Control and Life Support MIIT Nanjing University of Aeronautics and Astronautics Nanjing210016 China Key Laboratory of Civil Aviation Emergency Science and Technology CAAC Nanjing University of Aeronautics and Astronautics Nanjing211106 China Environment Control System Research Department COMAC Shanghai Aircraft Design & Research Institute Shanghai201210 China

Aiming at the problem of sensor layout in an emergency flotation system, a sensor layout scheme design method based on the NSGAII method is proposed. The ALE method is used to simulate the water landing process of the helicopter on different pitch angles. The logic relationship of the 4/5 voting system is used to improve the sensor module reliability. Further, a mathematical model of layout scheme is established to maximize the detection coverage and minimize the force acting on the water immersion sensors when helicopter emergent water landing as the objective functions. Based on the mathematical model of water immersion sensor layout optimization constructed in this paper, NSGAII is used to solve this problem. The results show that the proposed method can realize the optimization of the layout of the water immersion sensor, the detection coverage of optimized schemes is increased by 3.26% on average compared with the value under the original scheme, and the force acting on the water immersion sensors is reduced by 61.86%. © Published under licence by IOP Publishing Ltd.

关键词： Flotation

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Numerical simulation of impact of ejection seat rocket motor ignition shock waves on aircraft windshield loading

Numerical simulation of impact of ejection seat rocket motor...

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CSAA/IET International Conference on Aircraft Utility Systems (AUS 2024)

作者： Liang Wu Lou Jin Hang Xu Yibin Wu Overall Technology R&D Department AVIC Aerospace Life-support Industries Ltd. Xianyang 441000 People's Republic of China Aviation Key Laboratory of Science and Technology on Life-support Technology Xianyang 441000 People's Republic of China

ISBN: (数字)9781837242108

Aircraft windshield fragmentation during seat ejection can adversely affect crew ejection from the aircraft safety. In this paper, the shock wave loads caused by the firing of an ejection seat rocket motor were simulated numerically, and the numerical simulation flow was designed with the dynamic grid technique. The results show that the pressure peak of the inner surface monitoring point at the front end of the windshield is 9.4% lower compared with the test value at the same location when the rocket engine is firing at 0 km/h velocity ejection, which proves the numerical simulation method feasible. The effects of rocket pack ignition shock waves on the aircraft windshield can be divided into shock wave loading phase and quasistatic pressure loading phase. The former has a large peak load and a short duration, while the latter has a small peak load and a long *** corners within the cockpit, converging phenomena occur during shock wave propagation, and the area near the cabin inner wall at the front and sides of the aircraft's windshield is more heavily loaded and has a higher risk of damage than other areas. The moment of maximum windshield loading for each calculated state is the moment of the first load peak. Due to the high velocity airflow blowing effect, the maximum windshield loading at 1100 km/h ejects is close to the zero velocity ejection value, acting in the opposite direction. The zero velocity ejection and impact loads at 1100 km/h eject should be emphasized in the windshield strength analysis.

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Multi-target Emergency Rescue Path Planning in Marine Wind and Wave Environments 3

Multi-target Emergency Rescue Path Planning in Marine Wind a...

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2022 3rd International Conference on Mechanical Engineering and Materials, ICMEM 2022

作者： Sun, Zhi Yu, Yuanyuan Mei, Yiying Xiao, Xunqiao Shi, Zicang Key Laboratory of Civil Aviation Emergency Science and Technology CAAC Nanjing University of Aeronautics and Astronautics Nanjing211106 China Key Laboratory of Aircraft Environment Control and Life Support MIIT Nanjing University of Aeronautics and Astronautics Nanjing210016 China

With the development of marine-related industries, the number of tasks at sea has increased, and accidents there happen more frequently as well. Search and rescue are very challenging because of the extreme wind and wave environment at sea. Therefore, the state has been paying more attention to maritime emergency rescue. One part is emergency rescue path planning, which is crucial for helicopter emergency rescue at sea. In this paper, a series of multi-target rescue path solutions are created in order to solve the challenge of multi-target rescue path planning while taking into account sea wind and waves. The rescued targets' floating trajectory model is first established. Then, a recursive algorithm based on a permutation tree is given in response to the unsteady change of the targets' position at sea. The rescue path is planned with the goal of cutting down on the helicopter's search time. Finally, using the multi-target rescue in China's Taiwan Strait as an example, it is discovered that the overall time needed for the multi-target rescue is decreased by 7.03 minutes, and the efficiency of the rescue is improved by 13.3% in the wind and wave environment at sea. According to the research, the optimal rescue path shortens the time required for multi-target rescue at sea while increasing the effectiveness of helicopter rescue operations. © Published under licence by IOP Publishing Ltd.

关键词： Motion planning

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Electrochemical Characteristics and Corrosion Resistance of Alznpbsn High Entropy Alloy in Nacl Solution

SSRN

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SSRN 2024年

作者： Yao, Xiaofei Wang, Weihua Qi, Xiaoling Ma, Yufei Yang, Wei Lv, Yunkun Liu, Yongqin Chen, Jian School of Materials Science and Chemical Engineering Xi’an Technological University Shaanxi Xi’an710021 China Aviation Key Laboratory of Science and Technology on Life-support Technology Hubei Xiangyang441003 China

An innovative corrosion resistance AlZnPbSn high-entropy alloy was prepared that microstructure was characterized, the corrosion resistance was tested. The microstructure of AlZnPbSn alloy is dendritic, eutectic and peritectic, and the composition phase of AlZnPbSn alloy is FCC solid solutions. The corrosion form of AlZnPbSn high-entropy alloy in NaCl solutions of different concentrations is general corrosion, and the corrosion surface is loose and undense. The corrosion products attached to the corrosion surface of alloys are mainly composed of Al and Zn oxides. Sn and Pb are corroded to form Sn and Pb oxides, which dissolve or fall off to form micro-holes or pores on the corrosion surface of AlZnPbSn high-entropy alloy. With increase of NaCl solution concentration, the degree of corrosion products fall off or dissolve increase, so the corrosion rate of AlZnPbSn high-entropy alloy increase. In 10.5% and 14%NaCl solutions, the amount of Al oxides in the corrosion products increase, a locally dense corrosion product was formed on the corrosion surface of AlZnPbSn high-entropy alloy, but which cracked and could not protect the matrix. Therefore, the locally dense corrosion products on the corrosion surface of AlZnPbSn high-entropy alloy in NaCl solutions could not improve the corrosion resistance. © 2024, The Authors. All rights reserved.

关键词： High-entropy alloys

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Simulation research on the performance of ejecting inflation system of emergency evacuation slide

Simulation research on the performance of ejecting inflation...

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CSAA/IET International Conference on Aircraft Utility Systems (AUS 2024)

作者： Lou Jin Qilong Liu Liang Wu Overall Technology R&D Department AVIC Aerospace Life-support Industries Ltd. Xianyang 441000 People's Republic of China Emergency Rescue Technology R&D Department AVIC Aerospace Life-support Industries Ltd. Xianyang 441000 People's Republic of China Aviation Key Laboratory of Science and Technology on Life-support Technology Xianyang 441000 People's Republic of China

ISBN: (数字)9781837242108

In this article, the CFD method is used to analyse the performance of the ejecting inflation system of the emergency evacuation slide. The simulation model is established according to the operating principle of the ejecting inflation system. Quantitative analysis of the applicability and accuracy of simulation models in the performance simulation of the ejecting inflation system is carried out, and the effects of different ejection pressures and ejection working fluid components on the system performance are simulated. The research results show that the Realizable k-e model has the smallest simulation deviation, and the ejection flow rate and ejection ratio are within 5% of the experimental value, which meets the requirements of engineering development; increasing ejection pressure is beneficial to increase the ejection flow rate and speed up the inflation of the slide, but the ejection ratio will decrease when the ejection pressure pass 3.75MPa, which is not conducive to reducing the weight of the system; increasing the N2 content in the ejection gas source is beneficial to increase the ejection ratio and reduce the weight of the system while ensuring the inflation performance. The research results of this article can provide a theoretical basis for the determination of the design index of the ejecting inflation system of the emergency evacuation slide.

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NUMERICAL SIMULATION AND EXPERIMENTAL RESEARCH OF SHEAR-DRIVEN WATER FILM ON FLAT PLATE

NUMERICAL SIMULATION AND EXPERIMENTAL RESEARCH OF SHEAR-DRIV...

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

作者： Li, Qinyang Guan, Ning Ning, Bo Zhu, Guangya Zhang, Dalin Chen, Weijian Key Laboratory of Aircraft Environment Control and Life Support MIIT Nanjing University of Aeronautics and Astronautics Nanjing China College of Aeronautics Shandong Jiaotong University Changqing University Science and Technology Park No.5001 Haitang Road Jinan China Utility System Design and Research Department Jiangxi Hongdu Aviation Industry Group Company Ltd. Nanchang China

The supercooled water droplets in the air will form a water film on the aircraft during flight, which will then form icing, which will have an impact on the aerodynamic performance of the aircraft and even endanger the flight safety. In this paper, based on the Eulerian Wall Films model, the partial wetting effect is introduced, and the water film flow on flat plates driven by airflow shear force is investigated. The flow behaviours of water film with different contact angles under different flow rates were explored through water film test. The effectiveness of the calculation method for water film flow characteristics in this paper was verified by comparison between numerical simulation and test records, which laid a foundation for the anti-icing calculation in subsequent studies. © The Institution of Engineering & technology 2024.

关键词： Shear flow

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Effects of Heat Treatment Cooling Methods on Precipitated Phase and Mechanical Properties of Cocrfemnni-Mo5c0.5 High Entropy Alloy

SSRN

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SSRN 2023年

作者： Yao, Xiaofei Wang, Weihua Qi, Xiaoling Lv, Yukun Yang, Wei Li, Tianye Chen, Jian School of Materials Science and Chemical Engineering Xi’an Technological University Shaanxi Xi’an710021 China Aviation Key Laboratory of Science and Technology on Life-support Technology Hubei Xiangyang441003 China

CoCrFeMnNi-Mo5C0.5 high entropy alloys were prepared by vacuum arc melting, and then which heat treatment were carried out by water cooling, air cooling and furnace cooling respectively. the microstructure and phase composition of as-cast and heat treated CoCrFeMnNi-Mo5C0.5 high entropy alloys were examined by SEM, EDS and XRD, the mechanical properties of as-cast and heat treated CoCrFeMnNi-Mo5C0.5 high entropy alloys were tested by the tensile test and hardness test, and the effects of heat treatment cooling methods on precipitated phase and mechanical properties of CoCrFeMnNi-Mo5C0.5 high entropy alloys were investigated. The results show that precipitated phase in CoCrFeMnNi-Mo5C0.5 high entropy alloys is MC phase, which are riches in Mo, Cr and C. With change of heat treatment cooling methods from furnace cooling, air cooling to water cooling respectively, the heat treatment cooling rate is increased, the amount and size of precipitated phase are all decreases, and the position of precipitated phase change from grain boundary to intragranular. The tensile strength and elongation of heat treatment water cooled CoCrFeMnNi-Mo5C0.5 high entropy alloys are 739MPa and 41% respectively, which are realizes the simultaneous increase of strength and plasticity. With increase of heat treatment cooling rate, the hardness of CoCrFeMnNi-Mo5C0.5 high entropy alloys decrease, the elongation increase, the plastic deformation occurs mainly in the uniform plastic deformation stage. The fracture mode of as-cast CoCrFeMnNi-Mo5C0.5 high entropy alloy is intergranular fracture, the fracture mode of heat treatment furnace cooled, air cooled and water cooled CoCrFeMnNi-Mo5C0.5 high entropy alloys are all transgranular fracture. © 2023, The Authors. All rights reserved.

关键词： Iron alloys

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RESEARCH ON OPTIMIZATION technology FOR CONTROL PARAMETERS OF EJECTION SEAT BASED ON PSO ALGORITHM 32

RESEARCH ON OPTIMIZATION TECHNOLOGY FOR CONTROL PARAMETERS O...

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32nd Congress of the International Council of the Aeronautical Sciences, ICAS 2021

作者： Jin, Lou Wu, Ming Yang, Hui Wu, Liang Cui, Dongyue Overall Technology R and D Department AVIC Aerospace Life-support Industries Ltd. Xianyang441000 China Aviation Key Laboratory of Science and Technology on Life-support Technology Xianyang441000 China Institute of Mechanical and Electrical System AVIC The First Aircraft Institute Xi'an710000 China

ISBN: (纸本)9783932182914

This article studies the optimization simulation method of the multi-modal control parameters of a certain type of ejection seat. According to the working mechanism and optimization goals of the seat, based on the particle swarm optimization algorithm, an optimized simulation program is designed. Using an optimization simulation program written by the Matlab/Simulink platform, the preliminary determination, screening and iterative optimization of control parameters were completed. The optimization results show that by optimizing the multi-modal control parameters, the life-saving performance of the seat is increased by 12.5%, which verifies the effectiveness and feasibility of the optimization algorithm, and provides a theoretical basis for future seat development and modification.. © 2021 32nd Congress of the International Council of the Aeronautical Sciences, ICAS 2021. All rights reserved.

关键词： Ejection seats

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A Novel Cooperative MIMO Transmission Scheme Based on STBC for Event-Driven WSNs 3

A Novel Cooperative MIMO Transmission Scheme Based on STBC f...

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3rd IEEE International Conference on Electronics technology, ICET 2020

作者： Jun, Li Wujun, Xie AVIC Aerospace Life-support Industries LTD. Aviation Key Laboratory of Science and Technology on Life-support Technology Xiangyang China

ISBN: (纸本)9781728162836

The cooperative MIMO (CMIMO) technology having characteristics of low energy expended and high reliability can be very well suited to resource-constrained event-driven wireless sensor networks (WSNs), in which collecting date is unpredictable for space and time. A novel energy-efficient STBC-based CMIMO transmission scheme is put forward for event-driven WSNs in this letter, which adopts cross-layer design and dynamic event cluster. Detailed energy models are developed to maximize energy saving by the joint optimization for the number of cooperative nodes and constellation size. Through computer simulation, It can be found that the novel transmission scheme saves more energy in comparison with the traditional transmission protocol. © 2020 IEEE.

关键词： Wireless sensor networks

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Scalable parallel evolutionary optimization on high performance computing

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Aerospace Traffic and Safety 2024年第2期1卷 93-102页

作者： Chen Jin Daren Zheng Shuke He Ao Cheng Gang Liu Key Laboratory of Civil Aviation Emergency Science&Technology CAACNanjing University of Aeronautics and AstronauticsNanjingChina Zhejiang Scientific Research Institute of Transport HangzhouChina School of Computer Science and Information Technology RMIT UniversityMelbourneAustralia Key Laboratory of Aircraft Environment Control and Life Support MIITNanjing University of Aeronautics and AstronauticsNanjingChina Zhejiang Jiande Institute of General Aviation HangzhouChina Zhejiang ATM Sub-Bureau.CAAC HangzhouChina

To improve the efficiency of evolutionary algorithms(EAs)for solving complex problems with large populations,this paper proposes a scalable parallel evolution optimization(SPEO)framework with an elastic asynchronous migration(EAM)*** addresses two main challenges that arise in large-scale parallel EAs:(1)heavy communication workload from extensive information exchange across numerous processors,which reduces computational efficiency,and(2)loss of population diversity due to similar solutions generated and shared by many *** EAM mechanism introduces a self-adaptive communication scheme to mitigate communication overhead,while a diversity-preserving buffer helps maintain diversity by filtering similar *** results on eight CEC2014 benchmark functions using up to 512 CPU cores on the Australian National Computational Infrastructure(NCI)platform demonstrate that SPEO not only scales efficiently with an increasing number of processors but also achieves improved solution quality compared to state-of-the-art island-based EAs.

关键词： Parallel evolutionary algorithm High performance computing(HPC) Computational efficiency Asynchronous migration

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