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2023 | Book

Proceedings of the 10th Chinese Society of Aeronautics and Astronautics Youth Forum

Editor:  Chinese Society of Aeronautics and Astronautics

Publisher: Springer Nature Singapore

Book Series : Lecture Notes in Electrical Engineering


About this book

The Chinese Society of Aeronautics and Astronautics holds the Youth Science and Technology Forum biannually, which aims to assess the state of aviation science and technology, recognize advanced scientific and technological accomplishments, foster the development of young aviation science and technology talents, and provide a platform for young science and technology workers to track the frontier of science and technology, exchange novel ideas, and accurately meet the needs of the aviation industry.

This book contains original, peer-reviewed research papers from the conference. Topics covered include, but are not limited to, navigation, guidance and control technologies, key technologies for aircraft design and overall optimization, aviation test technologies, aviation airborne systems, electromechanical technologies, structural design, aerodynamics and flight mechanics, other related technologies, advanced aviation materials and manufacturing technologies, advanced aviation propulsion technologies, and civil aviation transportation. Researchers, engineers, and students find this book to be a useful resource because the articles provided here discuss the most recent advancements in aviation science and technology.

Table of Contents

Experimental and Modeling Study of Open-Hole Composite Laminates Under Tension

To study the failure behavior of open-hole carbon/epoxy composite laminate under tension, six pieces of open-hole composite laminates are tested, and the tension failure strength of every composite laminate is evaluated. Failure strength and damage phenomena of all composite laminates are examined. For all composite laminates, the failure phenomena is that the crack crosses the center hole transversely. The damage diffuses at the edge of the laminate composites. The main failure mode is fiber fracture and matrix cracking, with only a few delaminations. According to the experimental phenomenon, Hashin failure criteria and a stiffness degradation method are proposed to analyse the damage initiation and evolution of composite laminate. Finite element model is also established to simulate the failure propagation process of composite laminates. Compared with experimental data, a good agreement is achieved. Therefore, the finite element model established and the progressive failure method proposed in this paper can be applied to simulate the failure propagation process of composite laminates effectively.

Chen Fangyu, Jin Xiaowei
Research on Magnetic Tracking Algorithm Based on Double Transmitting Coils

IT is necessary to track the head position and attitude of pilots during the operation of aviation simulation aircraft. There are large errors in the distance between the transmitting coil and the receiving coil of the magnetic tracking pose tracking system. The six dimensional magnetic tracking position and attitude tracking system based on weighted dual transmitting coils can select the appropriate transmitting coils by weighting, so as to reduce the positioning and attitude errors of the system. The electromagnetic positioning method used in this paper is to measure the sine wave phase difference between the square of the synthetic magnetic induction intensity of the sensor and the square of the excitation signal of the magnetic field source, so as to accurately determine the six degree of freedom position of the target. The algorithm has the characteristics of stable performance and strong anti-interference ability.

Ranzhong Yao, Hong Liu, Jipeng Liu
Research on Hardware Drive Circuit of Electro-Hhydraulic Servo Controller for Aircraft Steering Gear

The research on the hardware drive circuit of electro-hydraulic servo controller for aircraft steering gear is carried out by means of functional analysis, principle design, circuit simulation and test verification. Firstly, the function analysis and principle design of the drive circuit are carried out from the level of electro-hydraulic servo control system and the control architecture of DSP(Digital Signal Processing)+DAC (Digital To Analog Converter) is defined in the design. Using discrete devices to build analog drive circuit, drive output and feedback, and finally form a closed-loop control current-type drive output mode. The mathematical model of the analog drive circuit is established, and the relationship between the drive output current and the control volage is obtained. The circuit simulation model is set up to verify the correctness of the circuit mathematical model. Finally, the controller hardware drive circuit is verified by setting up the test environment.

Fu Pinqing, Cui Wenjun, Yang Feng
Influence on the Flutter Characteristics of Hollow Fan Blade with Different Rib Number

The wide-chord hollow fan blade was one of the new technology which had been applied on the aeroengine. It could effectively improve the performance of aeroengine. The energy method had been used to analysis the influence of the different rib number on the flutter characteristic of the hollow fan blade. The results show that the hollow structure does not change the distribution location of the unsteady aeronautical power. The rib can improve the anti-vibration characteristics of hollow blade. When the rib number is four, the aerodynamic damping ratio is higher than the basic solid blade under the same phase angle which can extend the adaptive capacity for the poor working contexts.

Guo Xiao, Wu Meng-Di, Shi Yong-Qiang, Wen Zhen-Hua
Gas Ingestion Under Unsteady Rotor-Stator Interaction of Turbine Blade

Unsteady simulation of a 1.5 stage turbine with an axial cavity was conducted to illustrate the ingress mechanism under the blade-rotor unsteady interaction. The numerical approach was fist be validated by the experiment data. The pressure potential caused by the rotor blade plays a major role in externally induced ingress. The ingress area in the circumstance direction is rotated with the rotor blade, and the most serious ingestion would happen as the rotor leading edge and stator wake are close to each other. It is worth noting that a vortex would form in the situation that the ingress gas and sealing flow were both exit in the rim seal clearance. The rim seal vortex rotates from rotor wheel space to the stator side, as the result makes the ingress deeper near the rotor wheel space in rim clearance, which can be proved from the lower sealing efficiency near the rotor wheel space in the rim gap. Moreover, the rim seal vortex is mainly caused by shear in the gap. In addition to the tangential velocity gradient, the radial gradient also promotes the formation of rim seal vortex.

Tao Bai, Qing Zhen Yang, Jian Liu, Miaoer Wang
Hypersonic Vehicle Control Based on Deep Reinforcement Learning

The hypersonic vehicle is an important combat force in the future battlefield. At present, traditional guidance and control need to be designed prior to achieving the operational mission, lacking the ability of independent decision-making and rapid response, and not able to adapt to the development needs of complex battlefield situations in the future. With the rapid development of artificial intelligence, the decision-making ability of deep reinforcement learning has been applied in many aspects. In this paper, for the decision-making problem of autonomous flight maneuvering control of hypersonic aircraft, the deep deterministic policy gradient algorithm is used to design an autonomous flight maneuvering control decision-making algorithm to achieve the trajectory planning for the vertical climb and cruise tasks of the aircraft. Through the simulation test, the autonomous flight from the random initial position to the target position is realized, which proves that the training results have certain generalization. In the end stage, the longitudinal climbing section is extended to three-dimensional space, and the training simulation is carried out, showing the feasibility of the algorithm in the actual situation.

Xianlong Ma, Weijun Hu, Zhiqiang Gao
3D Design Engine Developed for Aircraft Conceptual Design Phase Based on Visual Basic and OpenGL

This article develops a 3D design engine for the software requirements of the aircraft conceptual design phase, introducing its development environment, capabilities, frameworks, coordinate axis definition, data structure, component drawing, etc. The applications of the 3D design engine are introduced at last.

Li Yueli, Wang Qi, Gao Yining
Research on Testing Technology for Noise Certification of Civil Aircraft

Aiming at the actual demand for noise certification of civil aircraft, the noise certification testing technology of propeller small aircraft and helicopters is mainly studied. Civil aircraft noise certification is mainly carried out in accordance with the provisions of CCAR-36, including two aspects of test system architecture and test flight method design. The qualification criteria in the noise certification test are mainly two points, one is that the noise data meets the restriction requirements of CCAR-36, and the other is that the measured track meets the method requirements of CCAR-36. An equivalent procedure for noise certification of small propeller aircraft is provided, and two specific implementation methods for determining the measured track are provided, which provide some effective references for noise certification of other types of aircraft.

Chunzhuang Zhao, Jiaxin Gao, Lei Wang, Tengyuan Liu
Research on Relative Navigation Technology of Air-Borne Missile in Satellite Denial Environment

Aiming at the problem of relative information acquisition in air-borne missile cooperative navigation, a cooperative navigation method in satellite denial environment is proposed. Taking the radar seeker and ranging data link for relative measurement and data transmission, the relative navigation state equation between the leader and the slave is designed employing master-slave structure. The measurement equations derivate based on ranging data link and radar seeker ranging. The relative deviation is estimated by Kalman filter. Finally, the simulation is conducted to verify the algorithm. The simulation results show that the proposed method could estimate the relative deviation between missiles where the relative position estimation deviation is less than 20 m, the relative velocity estimation deviation is less than 5 üm/s, and the relative attitude estimation deviation is less than 8′. The proposed method solves problems of obtaining the relative position, relative velocity and relative attitude error information of multiple missiles, and lays a foundation for realizing the cooperative detection of multiple missiles.

Haibin Cheng, Hao Lu
Numerical Simulation of Air Flow Field in High-Speed Aviation Tank

In order to quantify the increment of wind speed for high-speed trailer, this paper proposes to set sixteen measurement points of wind speed increment on it. Then, the experimental results are compared with those obtained by using the CFD method. It is shown in this paper that calculation results are 2% smaller than the ideal values obtained at different wind speed experimental points under the trailer, which leads to a wind speed increment steady region. Besides, the experimental and calculation results of wind speed increment are 8–10% smaller than the ideal values in this region, respectively. CFD shows feasibility and practicability in the analysis of air flow field for high-speed aviation tank. Surface crafts tend to be significantly affected by wind speed, such as seaplane, wing-in-ground effect ship, planning hull. Therefore, trailer front equipment can be used to mitigate the impact of wind speed on the test result.

Sheng-Zhe Shi, Fan Wang, Zai-Bin Zuo, Jun Jiao
Experimental Study on Low-Speed Wing Rock Characteristics of Low Aspect Ratio Flying Wing

Because of its high stealth and high aerodynamic efficiency, the low-aspect-ratio flying wing layout has become an advanced fighter development platform. The particularity of the layout reduces the lateral stability, which makes it face the instability of wing rock, and affects the maneuverability and flying quality of the aircraft. Therefore, it is necessary to study the wing rock characteristics of the low-aspect-ratio flying wing layout. Through various wind tunnel tests, the wing rock characteristics of the standard wing of the flying wing with low aspect ratio are comprehensively analyzed. The results show that there are sudden stall problems such as wing rock and wing drop in the low aspect ratio flying wing configuration, which are mainly due to the stable equilibrium point of zero-crossing of the rolling moment coefficient near the wing rock equilibrium position, and the zero-crossing of the rolling damping derivative. At the equilibrium point, the slope of the rolling moment coefficient is negative and stable.

Yanjie Shen, Chen Bu, Yanling Wang, Shuai Feng, Hao Chen
Study on Swaging Parameters and Vibration Characteristics of 0.25inch Civil Aircraft Hydraulic Pipe

For the dynamic response of hydraulic pipe, experts have a certain research foundation. However, for the research on the swaging repair of hydraulic pipe, the specific swaging parameters are not defined and analyzed in the manual. The research on the vibration characteristics of swaged pipe is almost blank. In this paper, the sine sweep experiment is carried out on a section of civil aircraft hydraulic pipe under typical swaging parameters, and the first six-order natural frequencies are obtained. Then, based on the basic principle of fluid-structure interaction, the modal analysis of the hydraulic pipe is carried out in ANSYS Workbench, the rationality of the Finite Element (FE) model is verified by comparing the simulation data with the experimental data. Taking the Swaging Length (SL) and Swaging Gap (SG) as the research object, 64 groups of hydraulic pipe models are established. Through modal analysis, it is determined that the maximum stress and strain of the hydraulic pipe is the pressure pipe joint, and the reasonable swaging parameters are obtained based on the actual swaging process. Finally, the harmonic response of the pipe model is analyzed based on the modal analysis results. It is found that the resonance is easier to occur at the first-order natural frequency, which is helpful to provide some references for the actual maintenance of aircraft hydraulic pipe.

Yu Lingjie, Chen Shikang, Wang Yuan
Dynamic Modeling and Longitudinal Stability Analysis of a Stratospheric Dual-Hull Airship

This paper provided a design of a dual-hull airship concept. It contained two traditional airships hulls that were connected in the middle by a wing, and had more control surface area than the traditional airship of the similar weight. In addition, the dual-hull airship’s yawing and pitching moments can be provided by changing directions and creating different thrust by four propulsion units combined with fins. Then a 6-Degree of Freedom (DOF) dynamic model for the dual-hull airship was described in this paper. It updated the estimation method of the added mass, force and torque (aerodynamic and propulsion unit’s thrust) of the dual-hull airship. The open-loop disturbance feature of the longitudinal mode simulated by Simulink and compared the the dual-hull airship’s added mass with the traditional airship of the similar weight. The results show that the dual-hull airship has less resistance and better flexibility than the traditional airship when they are flying forward.

Li Hang, Cui Yining, Hong Guanxin
Design of Pitch Angle Rate Control Law Based on L1 Adaptive Control Theory

Aiming at the problems of high-frequency oscillation easily caused by the traditional model-referenced adaptive control and the poor uncertainty and robustness of the traditional PID control model. This paper takes L1 adaptive control theory as the background and a scaled-down UAV in the laboratory as the object, first linearizes the UAV leveling to obtain the UAV longitudinal equations, then designs the pitch angle rate control law based on L1 adaptive theory, and designs a low-pass filter based on Liapunov's positive definite principle. Finally, perturbations and uncertainties are added to the model to verify the robustness and resistance to model uncertainties of the L1 adaptive control law, and compared with the traditional model-referenced adaptive and PID control methods, respectively. The results show that the designed L1 adaptive control system can still control the pitch angle rate well with the addition of disturbance and model uncertainty. And it ensures fast adaption with certain robustness and avoids the high-frequency oscillation problem brought by the traditional model-referenced adaption.

Liangliang Wang, Yuanxun Wang, Shuang Zhang, Wanling Gao
A Review of Electric Propulsion for Air Vehicle Research

Electric propulsion technology possesses the potential of high efficiency, low noise and low emissions. Distributed electric propulsion technology can not only provide the thrust required by the aircraft, but also the flexibility of power transmission, which makes the design of the aircraft from a larger dimension. Therefore, electric propulsion aircraft is one of the main development directions of future aircraft. Based on the electric propulsion method, the aerodynamic layout of the aircraft can be changed, and the flight efficiency can be improved by improving the lift-to-drag ratio, making the aircraft safer, more efficient, and low-carbon. This article reviews the development status of aviation electric propulsion vehicles, focusing on the characteristics of distributed electric propulsion technology and aerodynamic layout changes of electric aircraft.

Chen Xiao-li, Zhou Chao, Bai Cheng-an
Development of DNN Accelerator and Its Application in Avionics System

Future avionics systems must have high-performance intelligent data processing capability, especially for various intelligent application scenarios, such as image/radar target recognition, big data analysis, control and decision. Deep neural network (DNN) is a widely used AI algorithm due to its accurate fitness of nonlinear functions. It can introduce huge computation and memory costs as the increase of network depth. Recently, DNN hardware accelerator is proposed as a domain-specific accelerating platform. It can provide a flexible and reconfigurable operating environment for different algorithms, including convolutional neural network and recurrent neural network, with the advantages of high performance, low latency, and low power cost. The key technologies of DNN accelerators mainly include: parallel computing architecture, intelligent processing elements design, efficient memory structure, and dataflow scheduling optimization. This paper studies the design methodology of DNN accelerators, summarizes the key technologies, and discusses the prospective applications in avionics computing systems. This paper will provide some technique supports for the design of next-generation intelligent airborne computing systems.

Zhao Yixuan, Liu Feiyang, Gao Han
Research on Robust Adaptive Guidance Law Against Target Arbitrary Maneuvering

The augmented proportional navigation guidance law(APNGL), which is widely used at present, has poor robustness and large miss distance when it against escape target with large overload at the end of the trajectory. In order to solve this problem, firstly, the planar guidance model is established, a new guidance error is defined. Secondly, based on the principle of parallel approach method, a sliding mode adaptive guidance law is designed. In this process, there is no need to assume a target motion model or maneuver style, so the new guidance law is robust to target maneuvering and is suitable for engineering application. Thirdly, the miss-distance-index (MDI) is defined to evaluate the miss distance, and the guidance parameters are adjusted adaptively according to MDI. Finally, digital simulation was done in planar and 6-DOF, simulation results show that the designed guidance law has excellent guidance performance and can greatly reduce the average miss distance (the maximum can be more than 60%).

Zhang Peng, Lu Hao, Fu Shu Tang, Luo Xu Tao
Design for Brake Device of Rudder Pedal Based on Torsion Bar

As airborne equipment, the rudder pedal is used by pilots to control the rudder deflection by foot, and it has two functions of apply rudder and brake. As many disadvantages existing in traditional brake device, such as complex structure, large volume, heavy weight, a brake device of integrated rudder pedal based on torsion bar is designed. The device, using a torsion bar and an angular command sensor, realizes the brake device function of integrated rudder pedal. The design methods of spare functional parts of brake device are introduced in detail. The check calculation of torsion bar, design index of brake command sensor, kinematics simulation analysis of brake device and weight comparison after lightweight design are given. The practical application shows that the principle of the brake device is correct and it has the advantages of compact structure, high utilization, lightweight and high linearity.

Sun Ming, Zhang Wannian, Zuo Qiang, Liu Yuehua, Liu Fan
Calibration of Optical Testing System for Dynamic Impact Experiment of Aviation Seat

In this paper, a complete set of optical testing system calibration method combining three-dimensional control field design and space resection calculation program development for dynamic impact experiment of aviation seat have been formed, which can obtain high-precision calibration parameters of high-speed camera: exterior orientation elements, interior orientation elements and optical distortion coefficients, and the effectiveness and accuracy of this method were verified by tests. This research content provides important data support for the subsequent use of intersection method to solve the high-precision three-dimensional trajectory and attitude of the occupant head in the dynamic impact experiment of aviation seat.

Xiang Liu, Hongyi Gao, Rubing Wang, Shaoyin Wu
Flutter Analysis of Large Flexible Aircraft Based on Reduced Order Model

This paper developments approach for stable analysis in flight of large flexible aircraft. Considering geometrical nonlinearity, aircraft is divided into nonlinear wing components and linear fuselage component. Structural ROM method is used for wing structure modeling and nonlinear substructure method is used for comprehensive assembling wing ROM and fuselage linear modes together to obtain integrated aircraft dynamic equations. Non-planar double lattice method (DLM) is used as aerodynamic model. Stability analysis is based on the linearization around the trim configuration. The numerical results for a flexible flying wing aircraft model indicate coupling effects between rigid-body motions and elastic modes are important for this type of aircraft.

An Chao, Zhang Duoyao, Xie Changchuan
Bending Properties of Representative Composite Aircraft Structures Under Oil Pressure

Composite structures adjacent to the fuel tank of a helicopter fuselage experience a substantial bending load created by the oil pressure. Thus, these structures may undergo considerable deformation. The present study investigated the bending characteristics of typical structures (spar cap) adjacent to the fuel tank. The spar cap specimens (under two conditions) were subjected to four-point bending, and the strength and failure mode were examined. Test results shown that all samples fractured at the middle of the curved part under Condition 1, which was consistent with the working conditions of an actual structure adjacent to the fuel tank. Progressive failure analysis was performed based two-dimensional Hashin failure for intralaminar failure model and bilinear traction separation constitutive model is adopted for interlaminar failure model. The results shown that the appearance and internal damage morphology obtained by the simulation are consistent with experimental results.

Liu Han, Hui Qi, Shifeng Li, Zhen Zhang, Shaobo Gong
Impact Energy Absorption Features for Tensor-Skin Fuselage Box Structure

Finite-element software was used to conduct a simulated analysis of hard ground, soft soil, and water impacts for the composite tensor-skin fuselage box structure of helicopters; to study the energy absorption of the tensor skin in hard ground, soft soil, and water impacts; and to compare the accelerated velocity of the tensor-skin fuselage box structure under these impact conditions to establish whether the acceleration peak of the water impact is smaller than that of the hard ground and soft soil impacts. For the water impact, the well-designed tensor skin absorbs energy by stretching the fold area, so the tensor skin provides a greater advantage over a traditional skin in improving safety in helicopter impact. It is important to ensure that all wrinkles are spread successfully in the design of the tensor skin. A tensor ply spread is important for the tensor skin to absorb energy and to maintain structural integrity. The tensor skin offers greater safety advantages over traditional skins in helicopter crashes at the water surface.

Liu Han, Hui Qi, Shifeng Li, Kunfa Men, Jinliang Wang
ADS-B Anomaly Detection Algorithm Based on LSTM-ED and SVDD

With the rapid development of radio broadcasting technology and information technology, the possibility of ADS-B surveillance system suffering from radio frequency interference and network attack is increasing. Firstly, the types of attacks that ADS-B system is vulnerable to are analyzed, and the abnormal data of the corresponding state are simulated. Then, in order to detect ADS-B data attacks accurately, an anomaly detection algorithm based on Long Short-Term Memory Encoder–Decoder (LSTM-ED) and hypersphere classifier is proposed. Using the normal historical data to train the LSTM-ED model so that the reconstructed values can be obtained. Then, the difference values between the actual values and the reconstructed values are put into SVDD (support vector data description) for training, and a hypersphere classifier that can detect abnormal data is obtained. It is judged whether there is an abnormality according to the set threshold. Experiments show that the LSTM-ED-SVDD model can detect abnormal ADS-B data generated by various attacks and has high accuracy.

Jiao Yi, Lin Lin, Li Nisi, Wang Jintao
Influence of the Nail Hole Adhesive Layer on Mechanical Properties of Bonded-Bolted Hybrid Joint

The bonded-bolted hybrid joint with the nail hole glue layer is widely used in the overall fuel tank structure of the UAV wing due to its both bearing and sealing capabilities. During the service of the aircraft, the bonded-bolted hybrid joint is prone to breakage and debonding of the adhesive layer, which causes problems such as load-bearing and leakage. Based on the design of the thickness of the nail hole adhesive layer, this paper analyzes the variation law of the tensile load of the ordinary bolt and the high-lock bolt hybrid joint with the thickness of the adhesive layer, and uses the scanning electron microscope to observe the failure mode of the nail hole adhesive layer. The results show that for ordinary bolts, the tensile load is optimal when the thickness of the nail hole adhesive layer is 0.03 mm, while for high-lock bolts, the tensile load increases with the increase of the adhesive layer thickness in the range of 0–0.05 mm adhesive layer thickness. During the tensile failure of the joint, the cohesive failure of the nail hole adhesive layer and the debonding failure of the composite material-adhesive layer interface are the main factors, and the bonding performance of the titanium alloy and the adhesive layer interface is better.

Dang Xiaogang, Xu Jing, Wang Xi, Luo Bin, Zhao Di
Simulation Research on Air Distribution of Electronic Equipment Bay Ventilation System of Civil Aircraft

The electronic equipment bay ventilation system of civil aircraft is generally composed of a blowing subsystem and an extraction subsystem, which provides ventilation and cooling functions for the electronic equipment bay area. The quality of its design directly affects the reliability of the electronic equipment and thus directly affects the aircraft safety. In this paper, the electronic equipment bay ventilation system of a certain type of civil aircraft is taken as the research object, and the air distribution is investigated of the blowing subsystem and extraction subsystem. The Flowmaster is used to model the electronic equipment bay ventilation system, and the air distribution simulation of the blowing subsystem and extraction subsystem of the electronic equipment bay is carried out. The results show that, the air distribution simulation by using the restrictor ring size calculated by the flow balancing model can meet the air distribution design requirements of the electronic equipment bay ventilation system, and a reference for the design of electronic equipment bay ventilation system of civil aircraft is provided.

Jin Rongjia, Yan Xudong
High Cycle Fatigue Properties and Fracture Behavior of TC4 Titanium Alloy at Room and Elevated Temperatures

The high cycle fatigue properties and fracture characteristics of TC4 titanium alloy at room temperature, 200 ℃ and 400 ℃ under the stress concentration factors Kt = 1 and Kt = 3 were studied. The S-N curves of rotary bending fatigue under different conditions were plotted by power function fitting of three parameters, and the fatigue limit of Nf = 3 × 107 cycles was obtained. The results indicated that TC4 alloy had a high fatigue notch sensitivity at both room and elevated temperatures, which led to the significant decline of fatigue properties. It was found that the smooth specimen was more sensitive to the effect of temperature, whose high cycle fatigue performance decreased obviously with the increase of temperature. There was only one fatigue crack source region in the smooth specimen, and obvious fatigue bands and a small number of secondary cracks can be seen in the propagation region. With the propagation of cracks, instantaneous fracture occurred in the inner side of the specimen opposite the source region. Multiple fatigue crack sources were formed on the surface of the notched specimen, and then the fatigue cracks expanded from the circumference inward. Finally, instantaneous fracture occurred in the inner part of the specimen. TC4 alloy was characterized by ductile fatigue fracture.

Juan Li, Jianming Cai, Min Zhou, Rui Duan, Xu Huang
Analysis on Architecture Design and Evaluation Technology of Civil Aircraft Fuel System

Based on the fuel system architecture of civil aircraft, this paper forms the ability to establish the design and evaluation of aircraft fuel system architecture. Firstly, it is proposed to convert the stage results of demand development into the input of architecture design through demand analysis, then analyze the subsystems of the fuel system, including key design elements and trade-offs, and then form a structure. To further realize the mapping relationship between functions and components. In the process of architecture evaluation, based on the establishment of the system model and simulation analysis, the research on the comprehensive performance evaluation method of the fuel system is carried out, and the architecture trade-off evaluation is carried out, and finally a set of overall architecture design method of the civil aircraft fuel system is realized.

Li Zenghui, Wang Yong, Cheng Gang, Zhang Jianlan, Wang Pengbo, Cui Ze
Research on Beidou Short Message Interference and Power Optimization Control Method

AS ground-based civil aviation airborne navigation system gradually develops to space-based system, global satellite navigation system has become an important part of airborne navigation system. Beidou short message, as a unique function of Beidou satellite navigation system, can provide tracking function for aircraft. With the release of relevant CTSO, the modification of aircraft will be gradually completed. However, flight test found it is possible that Beidou short message has potential interference with GPS. In view of the above problems, the interference was first analyzed and reproduced in this paper, power optimization control method was proposed and verified through experiments. The experiment result shows that this method can solve the problem that Beidou short message interferes with GPS and has little impact on the success rate of short message communication.

Jiuyuan Guo, Zhan Zhang, Yaying Hu, Boyuan Gong
Robust Flutter Analysis Considering Control Surface Aerodynamic Uncertainty

To reduce the conservation of robust flutter analysis results, only the uncertainty of control surface unsteady aerodynamic was modeled. The $$\mu - k$$ μ - k approach was used to compute the robust flutter speed. The results indicate that robust flutter speed considering only the control surfaces unsteady aerodynamic is 716% less than entire surface case, also show that the approach for robust flutter analysis is applicable to multiple flutter modes in engineering practice.

Haigang Wang
Design and Performance Analysis of Aviation Axial Fan with Modified Variable Circulation Method

In aircraft oil cooling system, axial fan has been applied due to its characteristics of high rotation speed and pressure rise, as well as small flow rate and small volume. In this article, a modified variable circulation method for the aerodynamic design of axial fan with inlet guide vanes (IGVs) is newly developed. The design of aviation axial fan with advanced airfoil is performed based on a simplified three-dimensional (3D) flow theory. The effects of several different control parameters such as prewhirl parameters i.e. −0.75, −0.65, −0.55 and −0.45, circulation indexes i.e. 0.4, 0.45, 0.5, and number of IGVs and rotor blades i.e. R19S17, R17S15 and R15S13 on the fan performance are numerically analyzed in a systematic manner. The optimization design of axial fan with IGVs is proposed. Numerical study results indicate that the larger the prewhirl parameter and variable circulation index, the higher pressure rise and the wider effective working range of fan. The more the blade number, the higher pressure rise of fan, while the efficiency is normally kept the same. The effect mechanisms of above parameters on the fan performance are revealed. The current work can provide reference for the optimal design of advanced aviation axial fan.

Tang Jincheng, Xie Yongqi, Wu Hongwei, Gao Hongxia, Yu Jianzu
Geometrically Nonlinear Static Aeroelastic Analysis Based on CFD/CSD Interaction Accelerated by Panel Method

High-fidelity computational aeroelasticity based on CFD/CSD coupling method can capture the nonlinear effects in both aerodynamic and structural aspects. In this paper, geometrically nonlinear static aeroelastic problems of very flexible wings are solved based on CFD/CSD interaction accelerated by panel method. The acceleration of convergence is realized by introducing aerodynamic stiffness matrix based on panel method to reduce the computational cost of CFD. Considering the large deformation case, aerodynamic loads are applied as follower forces which change in direction along with the structural deflection. Geometrically nonlinear finite element method is employed for structural analysis. The numerical research of a high aspect-ratio wing is provided and the results are verified by the wind tunnel test data. Compared with the conventional staggered strategy, the proposed accelerated algorithm can improve the calculation efficiency under the same accuracy requirements.

Lan Yang, Changchuan Xie, Deli Liang, Chao An
Research on Design of New Low Frequency Broadband Electromagnetic Stealth Structure

Facing the demand of low-frequency broadband stealth technology is put forward for new generation weapon platform to improve the battlefield penetration and survival capability. Through scattering mechanism analysis, low-frequency broadband phase modulation microstructure design, broadband scattering angle control and travelling wave suppression fusion, the new low-frequency stealth structure is proposed. The suppression of backscattering of non-stealth shape and the goal of low-frequency broadband stealth are achieved, these technologies provide a technology path to improve low-frequency stealth performance of weapon equipment platform.

Zhang Qingdong, Liu Kaiye, Fangliang, Zhang Wenwu, Tian Junxia
Optimization of Flight Procedure Method Based on Track Clustering

Flight procedure devising is an important part to ensure flight safety, and the benchmark of aircraft safe operation. Therefore, if flight procedures are not suitable for the operating environment will also produce serious potential safety hazards. Based on the track information of the actual operation of an airport, combined with BP neural network and K-means algorithm, a new track clustering model is constructed. Through the cluster analysis of the departure track of the airport, the clustering center of the track is obtained. Combined with the inherent flight procedure of the airport, it is found that there are great differences between the actual operation track and the inherent flight procedure. After investigating and analyzing the causes of the differences, the program improvement scheme is put forward. Finally, the track clustering results are compared with the flight program optimization results, and the simulation analysis is carried out by using air top software. The results show that the new program can better adapt to the actual operation of the aircraft.

Cui Haiyang, Zhang Zhaoning, Lu Tingting, Meng Qingyu, Wang Jiechun
Simulation and Test Study on Composite Honeycomb Sandwich Panel

Composite honeycomb sandwich panel is one of the ideal and most efficient structural forms for aircraft structures. In this paper, a finite element analysis model of honeycomb sandwich structure is established. Firstly, the natural vibration mode and frequency of the model are calculated and compared with the test results. In order to verify the calculated acceleration and strain results, a response test of the honeycomb sandwich structure under vibration is further carried out. The simulation of the model is in good agreement with the experimental results, which verifies the effectiveness and accuracy of the proposed analysis and method.

Yang Kun, Yan Qun, Xu Fei
Guidance Law Design Against Unknown Maneuvering Target Based on Two ESOs

With the development of high maneuvering missiles and hypersonic maneuvering unmanned aerial vehicles, accurately intercepting such high-speed moving targets typically involves knowing the target's precise velocity and acceleration. Obtaining the velocity and acceleration of the target in real time is difficult and expensive in practice. On the other hand, developing a guidance law for maneuvering target with unknown velocity and acceleration is still a work in progress. This paper proposes three types of sliding-mode guidance rules based on two extend state observers (ESOs) for intercepting maneuvering targets with unpredictable velocity and acceleration, where the only information required is the LOS angle and distance, but not the LOS angle velocity or the relative velocity orthogonal to the LOS. To estimate the unknown things associated to the objective, two ESOs are built. The auxiliary signal system has been devised to compensate for the saturation constraint of the guidance command. To test the effectiveness and robustness of the proposed guidance legislation, numerical simulations are run with a non-moving target and a maneuvering target.

Chunhua Cheng, Mingming Huo, Dongsheng Hao, SiMin Bi
Numerical Study on the Formation of Defects During Double Diaphragm Forming Using a Biaxial Non-crimp Fabric

A macroscopic finite element model was employed to investigate the forming-induced macroscale defects during double diaphragm forming (DDF) using a bi-axial non-crimp fabric. The forming related wrinkling behaviour was predicted by the simulation considering the bending stiffness of the fabric. The location of wrinkles was influenced by the in-plane shear deformation and bridging force in the fabric-diaphragm assembly. The severity of wrinkles was influenced by the layup sequence and the frictional resistance at the fabric-fabric and fabric-diaphragm interfaces. The quad-axial layup [+45º/−45º, 0º/90º] was found to produce more wrinkles than the single-orientation layup, indicating that the dissimilar shear deformation between plies at different orientations can contribute to fabric wrinkling. A parametric analysis indicated that reducing the coefficients of friction at fabric-fabric and fabric-diaphragm interfaces can mitigate wrinkles. The deformation of fabric plies can be affected by the in-plane distance between preforms, when forming multiple components in one DDF operation. The component spacing therefore needs to be designed to ensure the quality of each preform is not adversely affected during multi-component forming.

Fei Yu, Xiangming Chen, Shuai Chen, Lee T. Harper
Research on Three-Proofing Technology Based on PCBA of Airborne Electronic Equipment

It is reported that 80% of airborne electric equipment failures have been linked to environmental factors. Adaptability to harsh environment has become an important tactical index for airborne electronic equipments. In order to improve the three-proofing properties (including moisture proofing property, salt spray proofing property and fungus proofing property),it is a must to improve the three-proofing effect in an all-round manner by means of rational structural layout, component design as well as PCBA design, process, production control, test verification. The three-proofing of airborne electronic equipment should be verified by tests in accordance with national military standards and other applicable standards so that requirements of environmental adaptability can be met. Meanwhile, data support can be provided for the upgrade of follow-up airborne electronic equipments.

Han Yaguo, Ding Lei, Wang Lu, Li Lanjun, Chen Xufan, Sha Jing
The Application and Research of Multi-core Processing in Avionics System

Multi-core processing is widely used for its high performance, but in avionics system, there are some time behavior interferences caused by cache sharing and bus sharing etc. To address application aspects of multi-core processing in avionics system, this paper made tests and analyses, which showed that dual-core processor can get doubled performance in some specified situations. Gathering service experience of multi-core processing in less critical system is also a usable way towards critical system. Then this paper presents a scheduling configuration of SMP mode multi-core AVIC OS to meet the needs of mixed critical applications. This envisioned that multi-core processing will support the development of next-generation avionics systems.

Zhan Wentao, Niu Wei, Yuan Ji, Wang Xiaobo, Yang Liu
Research on Hierarchical Control Strategy of Aircraft Power Supply System

With the iteration and improvement of the combat capability of fighter jets, the power of airborne electrical equipment has been continuously improved. At the same time, various advanced high-power equipment has been equipped with new fighter jets, making the electrical load power of the aircraft continue to increase. Aircraft power supply systems have many problems by using traditional control strategies such as low system efficiency and high energy consumption when faced with high-power loads. And their limitations are becoming more and more obvious. In this paper, based on the F-35 fighter power supply architecture and the typical airborne power load profile, the hierarchical control method is used to optimize the power supply system control strategy. The important indicators, such as average power, energy consumption, average efficiency and heat dissipation of the aircraft power supply system are greatly optimized, which greatly eases the pressure on the onboard power supply.

Liu Rui, Ai Fengming, Wang He, Liu Jiao, Wang Guan
Research on Electromagnetic Compatibility Technology Based on Airborne Electronic Equipment

As more and more types and quantities of airborne electronic equipment are used, the frequency band becomes more and more wide, and the radiation power becomes more and more large, which makes the electromagnetic environment where airborne electromagnetic equipment work become increasingly complicated. The electromagnetic compatibility of airborne electronic equipments should be well designed so that they can work normally in complex electromagnetic environment. In this paper, the basic concept of electromagnetic compatibility (EMC) is pointed out first of all, the fundamental principle of EMC is then analyzed, and finally the three elements of electromagnetic interference (EMI) and the basic methods of EMC design are put forward, which provides guidance for design of the follow-up airborne electromagnetic equipments.

Zhi Qiang, Han Yaguo, Wang Lu, Luo Kai, Yang Yuan
Research on Lift Error of Horizontal Tail Based on Component Disassembly Method

It is very important for calculating aerodynamic load and strength design to obtain aerodynamic force of aircraft components accurately. The aerodynamic force of horizontal tail is usually obtained by means of component disassembly in wind tunnel test, That is, subtract the value of non horizontal tail configuration from the value of whole plane configuration to obtain the value of horizontal tail. Using CFD method, through the comparative study of component disassembly method and direct measurement results, it is found that for low Horizontal tail aircraft, the slope of Horizontal tail lift line obtained by component disassembly method is more than 25%. The main reason for the error is that the component disassembly method assumes that the aerodynamic characteristics of the wing and fuselage with/without Horizontal tail configuration remain unchanged, so the interference data of the whole plane Horizontal tail on the fuselage and wing are accumulated on the Horizontal tail components. The error change of component disassembly method when the Horizontal tail is in different positions is studied. When the Horizontal tail is installed on the fuselage, the error is large, and when it is installed on the vertical tail, the error decreases gradually with the increase of height. By using the moment instead of the lift difference method that subtracted from the value of the whole plane configuration, the interference of the Horizontal tail to the wing can be basically eliminated and the interference of the Horizontal tail to the fuselage can be reduced. For the aircraft with T-tail layout, the results obtained by using the component disassembly method combined with the moment inverse calculation are the same as the direct measurement results.

Qing Wen, Kangzhi Yang, Zhihang Cheng, Yuanzhe Zhang
Influence of Temperature on the Ability of Flying Over Obstacles

Take off stage is a key stage in aircraft flight mission, and it is also a frequent stage of aviation safety accidents, so take-off performance has become one of the main contents of flight performance research. This paper mainly studies the influence of temperature on aircraft take-off performance, and makes take-off analysis for different types of airports, and draws the final conclusion that temperature has great influence on aircraft load and taxiing distance during take-off and landing, and explores the influence of temperature at different stages on aircraft performance during take-off.

Zhu Wenlong, Wang Haozhi
A Theoretical Fatigue Acceleration Method for Polymer Composite Materials

A theoretical fatigue acceleration method for polymer composite materials is proposed in this paper, based on continuum damage mechanics and time-temperature superposition. By way of demonstration, it has been applied to problems involving constant strain rates and fatigue loading conditions. The damage evolution law for the matrix of composites was constructed using the Weibull distribution of defects which will develop into cracks as a result of deformation. In conjunction with the Wiechert model, the theoretical framework formulated here is capable of capturing the mechanical behaviour of UD composites. Demonstration and initial verification of this acceleration method were carried out through experiments.

Xu Fei, Huang Guangqi, Xiong Huafeng
Research on CBB Mechanism Construction of Technical Service Organization

In the process of knowledge productization, the demand for modularized design of comprehensive knowledge service solutions is increasingly urgent in technical service institutions. Establish CBB definition, classification and hierarchical design for products, services and solutions. Put forward the design concept of “equal responsibility and right”, inspire the enthusiasm for the commercialization of scientific and research findings, form a return and a virtuous circle. Clarify the construction path, design a sharing platform, realize the module sharing and reuse of products and projects, improve efficiency, reduce costs and reduce risks.

Li Huijuan, Feng Bing
Service-Oriented Intelligent Avionics System Architecture

As the core component of the aircraft, the avionics system has gone through the independent, federated, and integrated architecture to deal with the increasingly complex air combat scenarios. With the development of artificial intelligence and integrated circuits, avionics systems should be prepared to equip a large number of intelligent applications, which contributes to more effectively completing the military missions. In addition, the next generation of avionics systems need to be more flexible, and thus can be conveniently updated and allow intelligent applications effectively communicate with each other. Therefore, to achieve a more intelligent and flexible avionics system, this paper proposes a novel Service-oriented Intelligent Avionics System Architecture, named as SIASA. With such a service-oriented architecture, SIASA provides a flexible software platform by treating intelligent applications as services. Specifically, the proposed SIASA consists of seven layers, i.e., airborne intelligent chip layer, abstraction layer, hashrate abstraction layer, equipment abstraction layer, airborne service capability layer, airborne intelligent application atomic service layer, and airborne intelligent application layer. With these layers, SIASA well supports intelligent applications and is able to make effective and efficient updates. Furthermore, SIASA also supports more advanced scenarios, including airborne OTA, drag-and-drop software development, and system intelligence.

Zhao Yan, Wen Pengcheng, Bai Linting, Wu Na
A Guided-Wave Based Damage Diagnosing Method with Energy Spectrum and Multi-scale Network

As a promising approach of structural health monitoring (SHM), Guided-wave is being widely used for damage diagnosis of carbon fiber reinforced composite (CFRP) in aeronautics. The traditional methods usually employ threshold for damage detection. However, as Guided-wave is easily influenced by structural and environmental factors, the man-made thresholds may vary significantly from case to case, which deteriorates its universal application. To overcome this weakness, a deep-learning-based method is proposed. Firstly, the sample is produced in the form of grey scale, so that its label is determined objectively rather than by human judgement. Secondly, it employs a multi-scale convolutional neural network with dedicated settings of kernel size and number of convolutional layers, which can effectively extract damage features from multi-dimensional signals while keeping the negative influences of increased network width low. Additionally, Gradient-class activation mapping (GRAD-CAM) technique is used to reveal the sample areas where the deep learning model concerns, which helps to interpret the physical significance of damage features. The experimental results demonstrate that the accuracy of damage identification and localization reaches 92.6%, which is superior to the traditional methods.

Lyu Shuaishuai, Yang Yu, Wang Binwen
Research on Health Monitoring and Intelligent Diagnosis Technology of Large-Scale Low-Speed Wind Tunnel

The large-scale low-speed wind tunnel test system is complex, involving many equipment, parameters, and data. In order to monitor the state of the system, quickly determine and locate the cause of the fault when the system is abnormal. Based on advanced sensors and network technology, this paper monitors the components and parameters of the system in real time. Through the three-dimensional simulation method, the digital twin system construction of the wind tunnel system including the model is realized, and the data visualization method is combined with the machine learning technology to intelligently predict and diagnose the faults and causes of the test data. Through the research in this paper, the technical foundation is laid for the construction of the smart wind tunnel laboratory.

Wang Jianfeng, Liu Boya, Liu Shi
Progress of Study on the Application of Actuators in Helicopter Airframe ACSRs

The severe vibration of helicopters have influenced the flight safety and the riding comfort. A good many technologies have been developed to suppress the helicopter fuselage vibration. They can be divided into two main types: active vibration control, passive vibration control. Now, the active vibration control technologies have been applied widely. The active control of structural response system (ACSRs) is one of the active vibration control technologies. It has many advantages, for example, no influence on rotor aerodynamics, and have been equipped in many helicopters. The actuator is a main component of ACSRs. There are many kinds of actuators, such as centrifugal inertial actuators, hydrostatic pressure actuators, electromagnetic actuators and piezoelectric actuators. Each kind of them have their own advantages and shortcomings, so they may be applicable to different helicopters. In this paper, the application of some kinds of actuators in helicopters, the basic principle, and the main performance parameters, such as output force are reviewed. A prospect of the development for the application of actuators in aviation for the future is made.

Hongyan Zhu, Qingli Wang, Xinhao Yu, Wei Hu, Zheng Liu, Gongnan Li, Yuqing Luan
Thermoelastic Analysis in Imperfect Rotating Functionally Graded Disks with Control Volume Finite Element Method

A control volume finite element approach (CV-FEM) for the thermoelastic issue in functionally graded material (FG) spinning disks have been developed in this work. Because of a technological constraint during the FGM production, the FG disks have porosities. Two main forms of porosity distribution (uniform and ununiform porosity distributions) along the radial axis of the rotating disk are considered. Due to the FG is often served in extreme temperature environment, the temperature-dependency material properties are considered in this study. The modified mixed model is used to determine the FG disk material properties involving the existence of porosity and temperature-dependency property effects. The effects of material distribution, mechanical and temperature loads, such as boundary temperature, FG gradient index, porosities distribution, and rotating angular velocity on the thermoelastic performance have been analyzed.

Qi Liu, Yanxia Du, Wenliang Qi, Lei Liu, Yewei Gui
A Survey of Few-Shot Learning for Image Classification of Aerial Objects

The aircraft has high requirements for effective detection and rapid support in different situations, and in this process, the image classification of aerial objects plays a very important role. In view of the situation that many tasks in the field of image classification of aerial objects cannot get enough samples to learn, it is necessary to study few-shot learning technology, which is mainly divided into three aspects: data based, model based and optimization based. Considering the advantages and disadvantages of various few-shot learning methods and their contribution to the accuracy of few-shot image classification, the developing trend of few-shot learning technology in the field of image classification of aerial objects is summarized. The three research directions of data, model and optimization are not independent of each other, and it is the mainstream to combine them. The application of few-shot learning technology in aviation can realize the deployment of high-precision and high-stability models for aerial tasks with little available data, and reduce the high cost of data tags to a certain extent, which is meaningful. It is hoped that this paper can provide ideas for the application of few-shot learning in the field of aerial image, and then solve practical problems.

Haoxin Cai, Xuanyue Zhu, Pengcheng Wen, Wei Han, Le Wu
Remaining Useful Life Prediction Method of Aero-Engines Based on LSTM

Fault diagnosis and remaining useful life prediction of aero-engines are important parts of its health management, which is of great significance for reducing maintenance costs and effectively preventing the occurrence of unexpected accidents. In order to improve the accuracy of engine fault prediction, this paper proposes a remaining useful life (RUL) prediction method of aero-engines, which is based on long short-term memory (LSTM) network. Firstly, in order to reduce noise and eliminate the influence caused by singular samples, the time-series in the dataset of aero-engines are processed by wavelet transform and normalization. Secondly, a LSTM prediction network is constructed, and the network is trained by clipping responses (i.e. RUL tag values) and adjusting network parameters. Finally, the RUL prediction is performed. A data set of aero-engines from practical engineering applications is used to validate the effectiveness of the proposed method. Compared with several other prediction algorithms, the proposed method in this paper effectively improves the prediction accuracy of RUL, and provides a decision-making basis for the maintenance of aero-engines.

Binghuan Duan, Yukai Hao, Yong Guo
The Optimization Design of Large-Camber Nozzle Based on Geometric Optimization

A large-camber nozzle is parametrically defined based on hyperelliptic equations and high-order continuous transition curves. Firstly, the transition curve that controls the geometric parameters of the nozzle is optimized, so that the nozzle has a smooth transition shape before aerodynamic optimization. Based on the geometric optimization solution, the optimization design of straight nozzle and large-camber nozzle is carried out with objectives of high thrust coefficient and high total pressure recovery coefficient. Compared with direct optimization, the work based on geometric optimization is more efficient and less time-consuming. The nozzle after geometric optimization with better thrust characteristics can be directly applied, which facilitates the rapid optimization design of nozzles in engineering.

Yang Yuxin, Chen Yesi, Ma Shoudong, Yang Hua, Wu Changju
An Offline Inverse Model for Identification of Multiple Pollutant Sources in Aircraft Cabins

Gaseous pollutant source identification is important to protect passengers from infectious agents in aircraft cabins. Current identification method may either suffer from numerical instability or require extensive prior knowledge. This paper proposes an offline inverse model, which needs no iterations to identify the locations and release profiles of multiple gaseous pollutant sources. The model first uses airflow field in the domain to construct a transport probability matrix by Markov chain, which contains the probability of pollutant transports through faces in each cell. Then the transient concentration responses at the monitoring points of a unit impulse releases from each candidate source can quickly be predicted by the transport probability matrix, to construct another matrix describes the relation between the source releases and the monitored concentrations. Finally, Tikhonov regularization is used to inverse the matrix for identification. The above model was applied on a two-dimensional aircraft cabin with gaseous pollutant released from two passengers. Results showed that the proposed model could correctly reproduce the detailed travel path of pollutant transport, as well as identify the locations and release profiles of multiple pollutant sources. More than 90% decrease of the computing time as compared with the conventional CFD method showed that the proposed model had high efficiency.

Yun Wei, Tengfei Zhang
Research on Data System and Platform Architecture of Complex Aeronautical Equipment Development

equipment is a typical representation of complex equipment, which is characterized by long development cycle, long service life, long industrial chain and many supporting contractors. In order to improve the internal and external cooperation and efficiency, the world's advanced aviation enterprises mostly adopt the single bill of materials (BOM), dual BOM and Data Lake configuration management mode; but there are still some problems such as lack of standard definition, one-way data transmission and difficulty in ensuring consistency. In order to solve the above problems, this paper proposes a multi-view xBOM architecture based on dual BOM infrastructure. On the basis of this multi-view xBOM architecture, a digital collaborative platform is established to implement standardized xBOM construction management and dynamic multi-view application. At present, the platform has been put into use in the development of a certain type of aircraft and has achieved the preliminary improvement of both quality and efficiency.

Li Rong-Qiang, Niu Shuang-Yue, Guo Ke-Zhi, Long Bin, Lian Xiao-Feng, Xu He-Yong
Simulation of Electro-Impulse De-Icing Process Based on an Improved Ice Shedding Criterion

, The electro-impulse de-icing (EIDI) system has wide development potential in the field of aircraft green de-icing. For the design and optimization of EIDI, it is quite necessary to study ice shedding criterion and simulate the de-icing process. Based on experimental observations and theoretical analysis, an improved ice shedding criterion considering ice/skin debonding and ice fracture is proposed in this paper. Nonlinear transient three-dimensional finite element models combined with the ice shedding criterion are established to simulate the de-icing process. The simulation method is verified by experiments and literature comparison. Compared with the traditional ice shedding criterion, the improved ice shedding criterion and de-icing simulation results in this paper are more reasonable and accurate. A parametric study is performed to determine the influence of ice strength parameters on de-icing effectiveness. The results of the parametric study can provide guidance for the design of a compound EIDI system with higher de-icing efficiency.

Yongjie Huang, Xian Yi, Qinglin Liu, Zhangsong Ni, Pan Pan, Ying Zhang
Resource Management in Cloud Computing Using Deep Reinforcement Learning: A Survey

Next generation aircrafts will not only require high-performance and intelligent computing capabilities, but also a fast design-developing-integration-update time cycle. Cloud computing technology provides a platform with large amounts of hardware resources and software services, making applications development and deployment much more convenient. Thus, airborne cloud computing becomes an important design methodology for next generation avionics system. However, the dynamic and uncertain cloud environment makes efficient resource management very complicated. Due to the characteristics of dynamic autonomous decision-making, deep reinforcement learning has become a promising resource scheduling algorithm. This paper firstly analyzes the requirements of airborne cloud computing systems, then studies the basic theory of cloud resources management and scheduling strategies. The resource management algorithms based on deep reinforcement learning (DRL), some common DRL models, experimental platforms, and evaluation parameters are introduced in details. Finally, some critical problems and challenges in the design of DRL-based resource management algorithm are summarized. This paper can provide some technique supports for the airborne cloud computing system.

Yuxin Feng, Feiyang Liu
Research on Analysis Architecture of Military Helicopter and Modeling Approach of Meta-Activity

In order to meet the architecture analysis requirements of military helicopter, the relationship of mission, system-of-system, system and measure is analyzed, and an analysis process is obtained. Then, based on DoDAF2.0 and Mission Engineering Guide, an analysis frame consists of 4 viewpoints and 14 models, is established. Meantime, the model expressions are given using UML diagram, mapping matrix or tabular form. Then, for the purpose of supporting basic and normal data for analysis architecture, the concept of metal-activity is proposed. Based on event-flow-chart, 7 modeling rules of metal-activities are established, including sequence rule, priority judgment rule, parallel rule, random rule, concentration rule, merge rule, and cycle rule. Finally, the conclusion is given that the analysis architecture is appropriate for military helicopter and can be referred by other weapon system.

Benchao Lou, Qiang Sun
Spatial Temporal Characteristics and Driving Forces of CHINA’s Aircraft Industry

The development of China’s aircraft industry remained an increasing concern from the government and the public. Using the GIS method and the panel data from 2006 to 2019, this study visualized the spatial temporal characteristics of the aircraft industry in China from the following perspectives: the concentration ratio, the R&D intensity and the comprehensive development level. The characteristics were summarized as follows: (1) Across China’s 23 provinces and municipal cities, the average agglomeration degree maintained a relatively low level during the study period, but there was an uneven trend among different regions. The agglomeration degree was decreasing in traditional western production centers and increasing in the emerging eastern production centers. (2) The R&D intensity went up and down from year to year and varied significantly among different regions. (3) The comprehensive development scores in western China kept decreasing and those in eastern China maintained increasing.

Deng Yangu, Liu Guoliang She Ying, Jia Ling, Dai Lu
Flow Physics of a Top-Mounted Bump Inlet at Subsonic Cruise Condition

In order to explore the aerodynamic performance of the bump inlet with different angles of attack, a supersonic top-mounted bump inlet is designed. The objective of this study is to investigate the performance of the bump inlet under the subsonic cruise condition, especially including the flow characteristic with different angles of attack (AOA) in experiments and simulations. It is clear that the bump inlet could exclude the wall low energy boundary layer from both sides of the bump compression intake to ensure the airflow higher quality. Although the bump-induced flow filed is complex, it exhibits similar characteristics with smaller AOA. The total pressure recovery coefficient is decreasing with increase of AOA. In addition, the total pressure distortion at the aerodynamic interface plane is enhanced, but it has a tendency to decrease at small AOA. The turbulent intensity at the outlet enhances with increase of AOA. Moreover, under the same value of AOA, the internal airflow occurs separation at high back pressure, the bump inlet has higher total pressure recovery performance at low mass flow rate.

Longkai Guo, Yuan Yi, Peibo Yuan, Yaowu Zhu, Xingya Da
Research and Implementation of Temperature Control Method for Large Space Climatic Laboratory

The temperature control of aircraft climatic laboratory has the feature of big time delay, large temperature range and non-linear. A temperature control method of feedforward-cascade PID is proposed. Firstly, the model for temperature change of climatic laboratory is established through mechanism analysis, and the parameters of model are obtained based on step response curve identification method; Secondly, on the basis of analyzing the dynamic characteristics of the temperature control system, a two-stage refrigerant temperature control strategy based on constant flow and variable temperature is proposed, and a feedforward-cascade PID controller is designed; Finally, the controller parameters are obtained by the critical proportion method and trial-and-error method, then the controller is applied to the temperature control of the climatic laboratory. The results show that the control method can improve the dynamic response of the system and accurately track the desired temperature curve. This method has the advantages of fast response, no overshoot, high steady-state precision, and achieves the expected goal of temperature control.

Jingtao Wu, Binwen Wang, Xiangfu Wu, Yao Wang
Equivalent Thermal Conductivity Improvement of Stator Winding and Thermal Benefit for Air-Cooled Electrical Aviation Machine

Electrical machines with high power density are key enabling components of propulsion systems for flying cars. Air cooling system is widely utilized for electrical aviation machine for its compact and reliable composition. For air-cooled electrical machine, the equivalent thermal conductivity of stator winding is the main parameter in determining the thermal resistance inside the slot winding. To get a further understanding, the analytical evaluation method and improvement of the equivalent thermal conductivity of stator winding is studied. Furthermore, the influence of the improvement in equivalent thermal conductivity of stator winding on heat transfer path is investigated and thermal benefit and performance benefit are evaluated. The analysis shows that with the equivalent thermal conductivity of stator winding increases to 3 W/m·K, a 100 °C-temperature reduction can be achieved in the stator winding.

Xuanyang Hu, Chaofan Dong, Yuping Qian, Yangjun Zhang, Changjiang Wang, Weilin Zhuge
The Research Status and Development of Military Aircraft Ground Support Equipment

With the rapid development of aviation weapon equipment and the introduction of advanced technologies, new aviation support system concepts and support modes are emerging in recent years. Military aircraft support equipment is not only the material basis of an integrated support system for aviation weapon equipment, but also a significant factor affecting the combat effectiveness and the support cost. The improvement of support equipment performance and utilization rate contributes to the performance and the safety of weapon equipment. Ground support equipment carries a lot of basic support work and plays an increasingly important role in the ground support system. Combined with the research status of military aircraft ground support equipment, the configuration optimization of domestic military aircraft support resources and the status of ground support equipment standard system, this paper points out the main problems existing in military aircraft ground support equipment in China, and briefly describes the development trend of future aircraft support equipment, providing help and enlightenment for aviation support research.

Hongwei Liu, Hanlu Zhong, Jiayuan Wu, Bo Cheng, Zhengyu Zhou, Fanghua Cao
Design of an Electronically Beam-Scanned High-Power Capacity Reflectarray Antenna Based on Liquid Crystals for Airborne Radar Application

In this paper, an electronically beam-scanned high-power capacity airborne radar reflectarray antenna based on liquid crystals is presented. To achieving fast phase-tuning and high-power capacity performances of the airborne radar reflectarray antenna, the thoroughly simulated analysis of the structure of the patch and the position of the bias line is made. The optimized patch is rectangular patch with three rectangular slit, which shows good power capacity performance. And the bias line is placed at the center distance. Simulation shows that the introduction of bias line has little effect on the reflected amplitude and phase of the reflecting unite. A 11 × 11 airborne radar reflectarray antenna are designed and analyzed. The simulated results show that the power capacity of the reflectarray antenna is about 3.6 MW in air condition and 30° beam-scanning can be obtained. The results verify the electronically beam-scanned and high-power capacity performance of the airborne radar reflectarray antenna. The antenna shows good environmental adaptability and electronically beam-scanning performance.

Gexing Kong, Wei Du, Peng Cui, Yingfeng He, Rui Chen
An Controller Workload Forecasting Method Based on Flight Plan

The significant growth of air traffic volume in the next few years requires a more accurate method of controller load assessment. Under the current framework of pre flight plan management, the most important thing is to quantify the control work of controllers according to the flight plan and find a reasonable method to evaluate their work. We present a controller load evaluation method based on flight plan. The first part aims to analyze the elements of the flight plan that affect the work of the controller, and the second part will be devoted to evaluating the controller load according to the flight plan. Finally, the practical application will be discussed.

Heng Yuming, Wu Minggong, Wen Xiangxi, Lin Fugen
Research of Lateral Guidance Law for Small Aircraft

X-20 project designed by Cranfield University in England in 2021 is a supersonic business jet to meet the needs of commercial transports and private airlines. In this project, the flight management system is equipped as a critical part of the avionics system. Guidance laws in this system are always, decomposed into a lateral profile and a vertical profile. In the lateral profile, a guidance law is developed to track the straight path and the fix-radius transition which are components of a traditional flight path. The validation work of the guidance laws is carried out by simulation in MATLAB software. Then, the results show the efficiency and reasonability of the guidance algorithm.

Wenqi Lyu
Development of Wind Tunnel Dynamic Test System Driven by Electro-hydraulic Servo Motor

The nonlinear and unsteady dynamic aerodynamic characteristics are often associated with aircraft maneuver flight at high angle of attack and post stall flight. In view of the urgent need of the nonlinear and unsteady aerodynamic characteristics research for the development of advanced layout aircraft, a new wind tunnel dynamic test system driven synchronously by dual electro-hydraulic servo motors is developed based on FL-51 wind tunnel of AVIC Aerodynamics Research Institute, which can conduct dynamic derivative test, large amplitude oscillation test and post stall maneuver simulation test at high angle of attack with test model at the scale of 1.5 m under the wind speed range of 20–50 m/s. Based on the load’s rotational inertia and motion index of the test system, we design the hardware scheme of the control system and the position servo control algorithm, debug the performance index of the test system, and carry out the wind tunnel validation test with a low aspect ratio flying wing layout aircraft model. The debugging results show that the test system has good static/dynamic control precision, and the performance index and function achieve the design requirements. The Wind tunnel test results indicate that the test system can obtain the regular and rational test data of dynamic derivatives test and maneuver process simulation test, which can be used for the research of special aerodynamic characteristics of aircraft at high Angle of attack and post stall maneuver.

Hao Tan, Jianfeng Wang, Chen Bu, Yanjie Shen, Hao Chen
Study on Risk Control of the Horizontal Tail Coupling Flight Test

Parameter identification flight test is mainly to establish an accurate aerodynamic parameter model. The flight test method and concern is different with that in the certification flight test, which is to show compliance with the regulations. The parameter identification flight test risk is likely to be high. This paper discusses the flight test hazards of horizontal tail elevator coupling subject, and analyse the flight test risk. The horizontal tail jammed and horizontal tail stall are main risk in this flight test. The reason of those risks are analyzed in detail. The risk control method and risk mitigation plan, as well as flight test limitation and pre-flight test due to the risk mitigation plan, are introduced. In this process, the method of flight risk control is presented in this paper.

Dawei Zhang, Yi Su, Zhubin Fan
Research on Precise Servo Control Technology for Integrated Aircraft Utility System

In this paper, stepper motor servo valve is selected as the execution unit to adjust environmental variables, such as temperature, pressure and flow of the aircraft environmental control system and fuel thermal management system, to meet new generation aircraft requirements of the reliability of the servo valve, the controllability of the opening and closing angle, as well as the controllability of the opening and closing angle requirements. Since there are a large number and great variety of stepping motor controllers in the airborne system, a unified architecture design is adopted, and it is integrated into the Remote Execution Unit (REU) of the supporting equipment of the aircraft utility system, reducing the aircraft weight and improving the integration level. To enhance the accurate positioning and rapid isolation of stepper motor faults, a fault diagnosis method for inverse-time protection power drive circuit and hierarchical interface are designed to improve system safety and testability. To tackle the temperature rise, noise, torque ripple, start out-of-step and stop overshoot, caused by the stepper motor drive current distortion, high-deterministic command transmission technology and constant current drive technology based on fixed duty cycle and segmented pneumatic technology are developed to perfect the control accuracy of stepper motor servo valve. The test results show that the stepper motor servo control system designed in this paper has high control accuracy and better engineering application value.

Mingliang Hu, Wen Yan, Jionghui Che
Integral Sliding Mode Control for Antiskid Braking System of Unmanned Aerial Vehicles Based on Extended State Observer

This article addresses an integral sliding mode control (ISMC) method for antiskid braking system (ABS) of unmanned aerial vehicles (UAV) based on extended state observer (ESO) to track the real-time optimal slip ratio. First, based on reasonable simplification, a comprehensive dynamic model of the UAV braking system is established. Then, an ESO is designed to guarantee the precise estimation of uncertainty disturbance during aircraft ground taxiing, an ABS controller is generated by combining ISMC and ESO. Finally, simulation is carried out under different working conditions, including representative road, step reduction of braking torque, road changed suddenly, and parameter high-low bias. The simulation results verify the effectiveness of the proposed slip ratio control strategy.

Mingjun Xie, Yuhong Jia, Song Ding
Study on Mechanical Environment Analysis Method of Aircraft Cabin

In order to ensure the high reliability of aircraft, it is necessary to study the mechanical environment of aircraft. In this paper, the vibration and noise sources of the aircraft in cruise state are sorted out, and the external dynamic load of the typical mission profile of the aircraft is calculated by computational fluid dynamics simulation analysis combined with empirical formula method to obtain the aerodynamic noise load of the aircraft surface. Then, the low frequency response of the aircraft cabin is analyzed based on the finite element method, and the high frequency response of the aircraft cabin is analyzed based on the statistical energy method. The full frequency vibration and noise environment of the aircraft cabin is predicted, and the internal vibration and noise spectrum of the aircraft cabin is obtained. The detailed design method of cabin mechanical environment is established, which lays the foundation for the establishment of complete mechanical environment of the whole aircraft, and also provides a reference for the mechanical environment analysis of aircraft in high mobility and large overload environment.

Xiaoguang Zhang, Bin Li
Proceedings of the 10th Chinese Society of Aeronautics and Astronautics Youth Forum
Chinese Society of Aeronautics and Astronautics
Copyright Year
Springer Nature Singapore
Electronic ISBN
Print ISBN

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