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

作者： Jin, Lou Liu, Qilong Wu, Liang Overall Technology R&D Department AVIC Aerospace Life-support Industries Ltd. Xianyang441000 China Emergencv Rescue Technology R&D Department AVIC Aerospace Life-support Industries Ltd. Xianyang441000 China Aviation Key Laboratory ofScience and Technology on Life-support Technology Xianyang441000 China

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. © The Institution of Engineering & technology 2024.

关键词： Ejectors (pumps)

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RESEARCH ON AIRSPEED CORRECTION technologyOFEJECTION SEAT BASED ON CFD 34th

RESEARCH ON AIRSPEED CORRECTION TECHNOLOGYOFEJECTION SEAT BA...

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34th Congress of the International Council of the Aeronautical Sciences, ICAS 2024

作者： Jin, Lou Feng, Guanghui Wu, Liang Aviation Key Laboratory of Science and Technology on Life-support Technology Xianyang441000 China Overall Technology R&D Department AVIC Aerospace Life-support Industries Ltd Xianyang441000 China

A certain ejection seat airspeed sensing system is located in the wake flow field of the seat, andtheperceived static pressure will produce a large error from the local standard static pressure, requiringaerodynamic corrections to the sensed static pressure to ensure the accuracy of the measured velocityandaltitude parameters. In this paper, a technique to correct the static pressure of ejection seats duringejectionfrom the cabin is proposed, which combines CFD simulation and successive iterative approximationalgorithm. CFD simulation method was used to simulate the dynamic flow field during the seat egressfromcabin, and the total and static pressure data measured by the pitot tube sensing systemat ejectionvelocitybelow 3 Ma were analyzed. The total and static pressure values at different ejection speeds werecalculatedwith the principle of "total pressure taking the maximum and static pressure taking the minimum", andtherelationship curves of the static pressure correction coefficient with ejection velocity were obtained. Asuccessive iterative approximation algorithm was used to correct the measured static pressure basedontherelationship between the static pressure correction coefficient and the ejection velocity (Mach number). Thecalculation results show that the maximum error of perceived total pressure and static pressuresimulationvalues with test values is 2.5% at different speeds, and the maximum error of felt static pressuresimulationis 1.9%. The CFD simulation accuracy is high, and the simulation results can be used as input foraerodynamic correction. When the ejection velocity is less than Mach 3, the static pressurecorrectioncoefficient decreases monotonically with the ejection velocity increasing, and the successiveiterativeapproximation calculation converges. The maximum error between the static pressure correctionvaluecalculated by the successive iterative approximation algorithm and the static pressure at the test siteis3.8%, and the maximum error betwe

关键词： Ejection seats

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A hybrid piecewise FDD strategy for refrigeration charge fault of airborne vapor-compression cycle system

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INTERNATIONAL JOURNAL OF REFRIGERATION 2022年 135卷 164-173页

作者： Sun, Chengbin Wang, Hexu Jiang, Yanlong Gao, Zanjun Wang, Ju [a]Key Laboratory of Aircraft Environment Control and Life Support MIIT Nanjing University of Aeronautics and Astronautics 29 Yudao St. Nanjing 210016 China [b]Aviation Key Laboratory of Science and Technology on Aero Electromechanical System Integration Nanjing 211106 China

Many researchers have carried out study on refrigerant charge fault for variable refrigerant flow (VRF) airconditioning system, while few pay attention to refrigerant charge fault for vapor-compression refrigerant cycle system (VCS) of enhanced vapor injection (EVI) with a flash tank onboard. To develop a strategy for refrigerant charge fault of the above system, the optimization methods have been implemented to predict the refrigerant charge level (RCL) based on virtual refrigerant charge (VRC) models. Firstly, Pearson correlation coefficient analysis is employed to obtain the characteristic parameters. Secondly, a piecewise modified VRC model with the different characteristic parameters from VRC models is obtained for two cases of RCL < 75% and RCL > 75%. Meanwhile, combined with the principal component analysis (PCA) and the support vector machine (SVM) algorithm, a PCA-SVM model is developed to improve the prediction accuracy, and the average root mean squared error (RMSE) is only 7.8 compared to 14.9 of the modified VRC model when RCL > 75%, meanwhile, the correctly detected ratio is improved from 62.8% to 84.5%. Then, for solving the difficulty of fault detection and diagnosis (FDD) when RCL > 160%, the moving time window average (MA) algorithm is introduced and an online PCA-MA-SVM model is developed. Finally, a hybrid piecewise FDD strategy combined with three models for refrigeration charge fault in airborne VCS of EVI with a flash tank is obtained.

关键词： Vapor-compression refrigeration cycle system Enhanced vapor injection Refrigerant charge fault support vector machine Moving time window average

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Research on intelligent control technology for enhancing precision airdrop system autonomy 4

Research on intelligent control technology for enhancing pre...

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4th International Conference on Machine Learning and Computer Application, ICMLCA 2023

作者： Xu, Ronghua Yu, Gang Aerospace Life-Support Industries Ltd. Xiangyang China Aviation Key Laboratory of Science and Technology on Life-Support Technology Xiangyang China Hubei University of Arts and Science Xiangyang China

ISBN: (数字)9781510680265

ISBN: (纸本)9781510680258

The Precision Airdrop System (PADS) is widely used in the accurate recovery of spacecrafts and the precision delivery of supplies. The accuracy of control is the core of the PADS achieving the precision airdrop. To enhance control accuracy, an intelligent control technology for enhancing PADS autonomy based on simulation environment is developed. The dynamic model employed to calculate the PADS state is a 6-degree-of-freedom (6-DOF) model, and the reinforcement learning control training method is based on the A-C architecture. Through analysis of simulation results in both windless and windy environments, it is evident that the reinforcement learning control strategy based on the AC architecture outperforms the traditional PID strategy. The analysis highlights the challenges posed by wind in achieving precise control and presents an effective approach for enhancing PADS autonomy through intelligent control. © 2024 SPIE.

关键词： Intelligent control

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Study on Simulation Method to Determine the Inflation Threshold of Head Protective Airbag for High-speed Helicopter Pilot 2

Study on Simulation Method to Determine the Inflation Thresh...

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2022 2nd International Conference on Mechanical, Aerospace, and Automotive Engineering, CMAAE 2022

作者： Feng, Zhijie Fan, Chengcheng Ke, Chuanyi Zhang, Haibo Liu, Tao AVIC Aerospace Life-Support Industries LTD. Xiangyang441000 China Aviation Key Laboratory of Science and Technology on Life-Support Technology Xiangyang441000 China School of Aerospace Engineering Tsinghua University Beijing100084 China

Compared with ordinary helicopters, the flying speed of high-speed helicopters is increased from 350km / h to 450km / h, and the crash speed is bound to exceed 12.8m / s, which greatly increases the probability of collision injury of the pilots' head. The equipment, such as the traditional safety belts and crashworthy seats, cannot play an effective role in protection. In order to effectively improve the crashworthy survival rate of high-speed helicopter pilots, the main method in European and American countries is to design additional head protective airbags. The paper carried out the study on the simulation method for determining the high-speed helicopter head protection airbag inflation threshold value. Based on LS-DYNA, it has established the impact simulation model of the high-speed helicopter cockpit - seat - safety belt - pilot system. At the same time, the HIC value of the dummy head (no more than 1000N) and the pull force of the shoulder strap (no more than 8890N) are taken as the objective function to simulate the collision process of the man/seat system in multiple states of the high-speed helicopter. Finally, the inflation threshold of the head protective airbag is determined, which provides a critical support for the development of the head protective airbag. © Published under licence by IOP Publishing Ltd.

关键词： Helicopters

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Simulation study on dynamic opening characteristics of airplane drag chute under the condition of stable crosswind

Simulation study on dynamic opening characteristics of airpl...

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CSAA/IET International Conference on Aircraft Utility Systems 2020, AUS 2020

作者： Jin, Lou Yang, Pin Hu, Xuepeng Li, Hui Zhang, Linling Cui, Dongyue Aviation Key Laboratory of Science and Technology on Life-support Technology Xianyang China AVIC Aerospace Life-support Industries Ltd. Xianyang China AVIC The First Aircraft Institute Institute of Mechanical and Electrical System Xi'an China

ISBN: (纸本)9781839535635

In this paper, the ALE fluid-solid coupling algorithm is used to realize the simulation of the dynamic opening process of a certain type of airplane drag parachute. Based on the drag parachute working principle and folding process, a finite element model of the main parachute in the installed state is established. In the LS-DYNA software, the parachute opening characteristics of the drag parachute were simulated and analyzed under no crosswind conditions and Stable crosswind conditions at speed 10m/s. The results show that, under the condition of no crosswind, the error of the important parameters such as parachute straightening force, parachute opening dynamic load, parachute deflection angle and test data is less than 15%, and the simulation accuracy meets the engineering development requirements. On this basis, the parameters such as the unfolding shape, deflection angle, and stress state of the parachute parachute under stable crosswind conditions, which are difficult to test and simulate, were studied. This will provide a theoretical basis and technical approach for drag chute design and other types of parachute product research. © 2020 Institution of Engineering and technology. All rights reserved.

关键词： Product design

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A Health Assessment Strategy for Helicopter Emergency Floatation System

A Health Assessment Strategy for Helicopter Emergency Floata...

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International Conference on Guidance, Navigation and Control, ICGNC 2020

作者： Ding, Qiyan Sun, Zhi Cheng, Lihong Lu, Ningyun Jiang, Bin College of Automation Engineering Nanjing University of Aeronautics and Astronautics Nanjing210000 China Key Laboratory of Aircraft Environment Control and Life Support MIIT Nanjing University of Aeronautics and Astronautics Nanjing210016 China Aviation Key Laboratory of Science and Technology on Life-Support Technology Xiangyang441003 China

ISBN: (纸本)9789811581540

When taking salvaging missions, helicopters play important roles but still face high risk because of complex circumstance. Emergency Floatation System (EFS) is critical to ensure flight safety and conduct emergency rescue for helicopters. To achieve this goal, the reliability of EFS itself is the first concern during its design and development. This paper presents a health assessment strategy for EFS of helicopters, based on multi-signal flow graph modeling, fault tree based diagnosis and Bayesian Networks (BN) based assessment. The simulation results can show that the developed strategy is feasible to evaluate the health status of EFS, which will be helpful for the maintenance division to take proper precautions to avoid potential accidents. © 2022, The Editor(s) (if applicable) and The Author(s), under exclusive license to Springer Nature Singapore Pte Ltd.

关键词： Bayesian networks

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

作者： Wu, Liang Jin, Lou Xu, Hang Wu, Yibin Overall Technology R&D Department AVIC Aerospace Life-support Industries Ltd. Xianyang441000 China Aviation Key Laboratory of Science and Technology on Life-support Technology Xianyang441000 China Ejection Lifesaving Technology R&D Department AVIC Aerospace Life-support Industries Ltd. Xianyang441000 China

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. © The Institution of Engineering & technology 2024.

关键词： Ejection seats

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Equivalent study on delethalization test for sled head injury criteria test of civil aircraft passenger seat

Equivalent study on delethalization test for sled head injur...

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CSAA/IET International Conference on Aircraft Utility Systems 2020, AUS 2020

作者： Jin, Zhi-Sheng Shen, Wen-Bo Luo, Guo-Xiong Li, Ming Jia, Zhi-Xiao Zhou, Wu Jia, Luo Zhang, Le Aviation Key Laboratory of Science and Technology on Life-Support Technology Xiang yang China Test Department AVIC Aerospace Life-Support Industries Ltd No.29 Xinhua road Xiang yang China Science and Technology Development Department AVIC Aerospace Life-Support Industries Ltd No.29 Xinhua road Xiang yang China

ISBN: (纸本)9781839535635

The equivalent study between delethalization test and sled HIC test is in order to improve the efficiency of Head Injury Criteria (HIC) test on civil aircraft passenger seats, as well as to reduce the test consumption and cost. The equivalent impact model was established based on the equal rotatory kinetic energy, then the test of equal energy impact was designed and the delethalization test was carried out. The results of delethalization test and sled HIC test show that all the deviation value of HIC, peak head center of gravity (CG) acceleration in X direction, peak head CG resultant acceleration and the deformation of the seat back (C/B) was within ± 20%. In conclusion, the equivalent impact model in this paper is suitable, and the delethalization test be used as an equivalent method for sled HIC test is feasible. © 2020 Institution of Engineering and technology. All rights reserved.

关键词： Kinetics

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Research on residual design of ignition circuit of ejection seat 24

Research on residual design of ignition circuit of ejection ...

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5th International Conference on Computer Information and Big Data Applications, CIBDA 2024

作者： Wang, Wensheng Wu, Shuanglong Li, Jin Jin, Liying Aviation Key Laboratory Science and Technology on Life-Support Technology Xiangyang Hubei441003 China Aerospace Life-Support Industries Ltd. Xiangyang Hubei441003 China Xiangyang Key Laboratory of Intelligent Manufacturing and Machine Vision Hubei University of Arts and Science Hubei Province Xiangyang441053 China

ISBN: (纸本)9798400718106

At present, the programmed ignition circuit is used in the ejection seat to stimulate the explosive materials. This paper analyzes the ignition circuit architecture of the parachute projectile fired by the electric detonator on the ejection seat, and puts forward two other feasible ignition schemes. Combined with the task reliability block diagram and model, the three schemes are respectively quantitatively calculated and qualitatively analyzed, thus the optimal fire scheme is determined. Then it provides a reference for the redundancy design of other parts of the ejection seat. © 2024 ACM.

关键词： Ejection seats

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