bluuebunny/crossref_metadata_2025_split huggingface dataset:
Study of critical deviation transfer for assembly of complex structural parts of aircraft
Authors: Huang Meng , Li Bo , Chen Xiaoyun , Zhuang Qineng , Guo Yanbing 
Published: May 2024

Abstract
In current assembly process of the aircraft complex structural parts, there are problems such as nonlinear, multilevel strong coupling and large uncertainty transfer relationship between assembly quality and its deviation sources. In this paper, an assembly deviation transfer method based on transfer entropy network graph is proposed to address the challenges. Firstly, the source of assembly deviation is analysed by constructing a multi-level assembly coordination network with assembly deviation detection data. Secondly, an assembly deviation propagation model is established by combining transfer entropy and complex network graph theory. This model provides insights into the topological relationship of assembly deviations and introduces causal metrics for evaluation. The effectiveness of method is demonstrated through its application in the assembly of an aircraft nose, thereby verifying its practicality and utility.
Development of flow metering for electric aircraft oil pump
Authors: Xuepeng Li , Wenlong Zhang , Yueming Cheng , Jianghong Li 
Published: May 2024

Abstract
In order to solve the difficulty of flow control in electric aircraft oil pump system, an electric aircraft oil pump was used as research object, with speed range of 2000rpm∼9000rpm, temperature range of 270K∼325K, pressure between the input and output of pump do not exceed 0.6MPa, and aviation 8B aircraft oil as medium. The influencing factors of aircraft oil flow were analysed, and an experimental system for researching flow metering methods was constructed. Based on the experimental data, an accurate flow metering model was established, which is significant for the metering and control of electric aircraft oil pump systems.
Modeling and evaluation of centrifugal pump performance degradation model based on stochastic process
Authors: Chen Xuan , Li Jia , Li Ping , Gao Limin , Chen Xiaolong 
Published: May 2024

Abstract
In order to clarify the performance degradation problem of fuel centrifugal pumps, a stochastic process-based performance degradation model modeling method is given with an aero-engine fuel centrifugal pump as the object of study, and the reliability assessment is carried out. First, the degradation modeling method based on stochastic process is given. Secondly, PumpLinx is utilized to obtain the performance degradation data of the centrifugal pump and perform data processing. Gamma and Wiener stochastic process models are given based on MATLAB. Finally, based on the centrifugal pump performance degradation data for centrifugal pump reliability assessment, and compare and analyze the advantages and disadvantages of the two modeling methods, and found that the degradation modeling method based on the Gamma process is more suitable for centrifugal pump reliability assessment.
Transient numerical investigation on thermochemical erosion of C/C nozzles in hybrid rocket motors
Authors: Jiang Xianzhu , Tian Hui , Ge Xuanhong 
Published: May 2024

Abstract
Nozzle erosion is a vital important issue that impacts the performance of hybrid rocket motors. Serious nozzle erosion may significantly decrease the combustion chamber pressure and thrust, which increases the difficulty in designing flight control systems. This paper aims to reveal erosion mechanism systematically. In this paper, transient numerical simulations of thermochemical erosion in hybrid rocket motors are conducted, and combustion flow and thermochemical erosion are coupled calculated. The numerical computation of combustion flow is based on the chemical reactions of propellants and regression rate model, and that of thermochemical erosion is based on the surface reactions between oxidizing species and carbon. The movement of burning surface and nozzle inner surface is simulated through dynamic mesh method. The hybrid rocket motor adopts 90% hydrogen peroxide and hydroxyl-terminated polybutadiene. Distributions of flow field parameters and fuel regression rate are given. The spatial developing process of nozzle surface is presented, and it is found that the roughness of nozzle profile increases with time. The nozzle wall temperature and wall pressure decline with time. Erosion by different species is calculated. OH and H2O make a major contribution to the nozzle thermochemical erosion, while nozzle erosion contributed by CO2 and O2 are quite low. Time-varying characteristics of the erosion rate are unveiled. At the first 1.5 s, the total erosion rate remains almost constant, and then it reduces over time.
Mathematical modeling and time-frequency characterization of aero-engine actuators
Authors: Pan P F , Li J , Guo Z B , Chen X L 
Published: May 2024

Abstract
The actuator is an essential part of the aero-engine control system, and its performance directly determines the efficiency of the whole system. The mathematical model of the aero-engine actuators, including electro-hydraulic servo valves, hydraulic cylinders, and actuators, is modeled and the time-frequency characteristics are analyzed using the Simulink module. Then, the system response is simulated and its time-frequency characteristics are analyzed. The simulation results show that the simulation error of the established actuator model is within the allowable range. The displacement response and the servo valve flow response fluctuate slightly near the steady state value, and the error value is only 0.857% at the maximum fluctuation value, and the system still works normally when a dynamic load is added to the system.
Distributed dynamic backup servo control for satcom-on-the-move systems
Authors: Ren Jiao , Ji Xiaoxiang , Li Jianghong , Han Lei , Wu Yafeng 
Published: May 2024

Abstract
This paper proposes a distributed control system for the servo control of the Satcom-On-The-Move (SOTM) systems. The servo control system is designed based on a distributed structure, which divides the control system into four sub-systems according to their functions. Each sub-system is equipped with a dedicated controller, and the controllers are connected to sensors and actuators via a bus. The control tasks of each sub-system are carried out by their respective controllers. To mitigate the impact of controller failures on the control system during running, a backup sub-system is implemented, which dynamically adjusts its function and state to ensure the normal running of the control system. An analysis of the impact of the switch to the backup sub-system on the stability of the control system under fault condition is presented. Finally, experimental analysis is conducted, and the results demonstrate the feasibility and effectiveness of the proposed design.
Study on laser ignition and combustion characteristics of micron-sized aluminum and Al-Mg alloys particles
Authors: Hou Fengting , Zhang Beichen , Feng Muyang , Liu Shuwei , Li Shipeng 
Published: May 2024

Abstract
In response to the problems of easy sintering and long ignition delay time of micron aluminum in the combustion of aluminum-containing propellants, choose the way to add magnesium to metal aluminum to construct an alloy system, through boiling, micro-explosions are generated during the ignition and combustion process to weaken the sintering behavior and shorten the ignition delay time of aluminum. Selecting aluminum and Al-Mg alloy powder fuel with a particle diameter of about 10 μm as the research object, a set of individual-particle fuel laser ignition and microscopic high-speed imaging experimental devices was built that can observe the whole process of ignition and combustion of micron-sized fuel. Thermal analysis was used to detect and characterize the thermal decomposition process of micron-sized aluminum and Al-Mg alloy powders; combined with the results of scanning electron microscopy, the difference in ignition performance of micron-sized individual particle aluminum and Al-Mg alloys was studied. Experiments have found that, compared with aluminum, the initial oxidation temperature of Al-Mg alloys is lower and the combustion is more complete. However, the effect of adding magnesium to aluminum is only reflected before 900 °C. The ignition and combustion images and flame propagation laws of micron-sized single-particle aluminum and Al-Mg alloys were obtained. It was found that adding magnesium shortened the ignition delay time, and the combustion produced less residual.
Analysis of landing gear walk vibration characteristics excited by aircraft anti-skid brakes
Authors: Wang Zhuangzhuang , Liu Xiaochao , Mei Haocong , Qiao Weizhi 
Published: May 2024

Abstract
Currently, there is not enough research on the mechanism that causes the vibration of landing gear walk when an aircraft anti-skid brake is activated. This paper aims to provide a comprehensive analysis of the characteristics of the landing gear walk and the associated research. It shows that the walk vibration is caused by a cantilever beam’s tip mass and that the study should focus on the landing gear walk’s characteristics. Firstly, according to the transverse vibration theory of cantilever beams, the transcendental equation for calculating the natural frequency of the landing gear can be obtained. After that, the influence of the structural parameters of the landing gear on each order of the natural frequency is analyzed. To ensure that the conclusions derived are applicable to all landing gear structures, the structural parameters are selected to cover both small unmanned aerial vehicles and large civil aircraft. Finally, the influence of the axial pressure of the landing gear on its inherent frequency is analyzed.
Durability analysis of large and medium-sized unmanned aerial vehicles based on load spectrum and probabilistic fracture mechanics
Authors: Xuanbao Wang , Liang Si , Jiaxing Wang , Zilong Wang , Shuo Wang , Ping Hu , Fanshun Duanmu 
Published: May 2024

Abstract
The analysis of unmanned aerial vehicle (UAV) durability is crucial for cost-effective repair and maintenance. Assessing the degree of damage and predicting the economic lifespan of a UAV is a critical component of its design and use. To evaluate the durability of large and medium-sized UAVs, data is gathered, and simulations are performed under real-world working conditions. The analysis includes creating a crack growth model for small cracks and determining the distribution of crack sizes, estimating the distribution of Time to Crack Initiation (TTCI), and calculating the general Equivalent Initial Flaw Size (EIFS) distribution. The results obtained from these analyses meet the UAV’s flight hour requirements and help to predict its economic life. This prediction is also beneficial for managing and maintaining the UAV’s life cycle.
Effect of U-shaped notches on nozzle performance and jet flow structures
Authors: Wu Zehuan , Wang Qimin , Wang Meili , Zhang Meihong 
Published: May 2024

Abstract
In nacelle design, optimization of nozzle shape is crucial for flow control. To understand the effect of nozzle shape on its aerodynamic performance and jet flow structures, the numerical experiment is performed using the dual separate flow reference (DSFR) nozzle released by the Aero Systems Engineering (ASE) FluidDyne Laboratory. A pair of U-shaped notches are made on the nozzle. The results show that the discharge coefficient and thrust angle increase with the size of the notches in all the simulated operating conditions. The notches induce a pair of streamwise vortices, which enhance turbulent mixing and decrease turbulent kinetic energy in the mixing layer.
Effects of wall transpiration on the supersonic boundary-layer oblique-type transition
Authors: Zhang Lun , Jiang Zhongzheng , Chen Weifang 
Published: May 2024

Abstract
The study of transpiration cooling is vital for the development of high-speed aircraft. In the current work, direct numerical simulation (DNS) is performed to investigate the impacts of wall transpiration on the boundary-layer oblique breakdown over a Mach 2 flat plate. The porous injection model is used to mimic the transpiration from the equally spaced circular pores. It has been observed from the numerical results that wall transpiration leads to the amplified growth rate of the imposed oblique mode waves, steady vortex waves, and other higher-harmonic waves. As a result, the occurrence of boundary-layer transition shifts upstream. Due to the presence of transpiration, the normal gradients of both streamwise velocity and temperature are decreased at the wall, which causes reduced skin friction and heat flux in the transpiration region. In addition, when upstream transpiration is present, reductions in skin friction and heat flux can also be observed within turbulent regions. This study provides insights into the DNS investigation on compressible boundary-layer natural transitions coupled with wall transpiration, and the results indicate that more systematic investigations addressing this problem are needed.
Study on setting method of temperature sensor in aircraft environmental control system
Authors: Zhang Xuan , Dang Xiaomin 
Published: May 2024

Abstract
This paper analyzes the working principle of each component of the aircraft environmental control system (ECS), takes the Boeing 737 aircraft as an example, and analyzes the distribution and role of temperature sensors in the aircraft ECS. Then, this paper presents a guideline for sensor setup suitable for each subsystem. The accuracy of the temperature sensor is measured, which verifies that the temperature sensor selection and set is reasonable and can ensure the good operation of the aircraft ECS.
Exploration of maintenance technology of aviation new energy power battery under machine learning
Authors: Song Shengli 
Published: May 2024

Abstract
The existing prediction models on the market have uncertainties and errors, which cannot accurately predict the remaining life of batteries. These problems lead to excessive or delayed maintenance of batteries, thereby affecting their performance and safety. Therefore, machine learning-based maintenance technology for aviation new energy power batteries has become a new research direction. This study used machine learning algorithms to construct a battery status classification and prediction model by collecting a large amount of aviation new energy power battery data. Through experiments, the model significantly improved its accuracy in battery status recognition tasks, with a maximum of 96%. It can accurately identify tasks such as battery health status, lifespan prediction, and fault detection. The model had made progress in balancing accuracy and recall, with a high F1 value. This meant that the model could accurately identify the abnormal state of the battery while minimizing misjudgment of normal batteries as much as possible. These research results provided important support for battery maintenance in the aviation field, with the potential to improve battery availability, extend service life, and ensure flight safety while reducing maintenance costs.
Simulation and analysis of the over-expanded flow field in asymmetric nozzles with lateral expansion
Authors: Yang Yalin , Yu Yang , Yu Tao , Mao Yuepeng 
Published: May 2024

Abstract
The study presented a numerical simulation of three-dimensional asymmetric nozzles featuring lateral expansion to investigate the flow field characteristics under over-expanded conditions and assess the influence of the lateral expansion angle. The research findings elucidate the distinct shape of the separation zones within the nozzle resulting from varying lateral expansion angles. In the restricted shock separation with separation bubbles forming on the flap pattern, the central separation bubble and corner separation bubbles exhibit independent characteristics. With an increasing lateral expansion angle under the same nozzle pressure ratio, the corner separation shock wave significantly impacts the shape of the central separation bubble.
Test and simulation of emergency flotation system buoy anti-overturning method
Authors: Yang Li , Huang Yanping , Sun Libing , He Fan , Zhu Yuanchun 
Published: May 2024

Abstract
The helicopter emergency flotation system can provide flotation capability after the helicopter accidentally falls into the water. During a test of a helicopter float in a submerged state, it was found that the vertical distance between the highest point of the contact point of the float and the aircraft and the lowest point of the cabin door was 0.59 m, which seriously hindered the entry and exit of the crew from the cabin door. To reduce the adverse effects of the pontoon flipping up on the occupants entering and exiting the hatch, it is envisaged to use restraint belts, add anti-rollover airbags, and design the anti-rollover airbags into triangles and saddle shapes respectively. Through theoretical analysis, the simulation method eliminated the triangle method for the connecting belt and the anti-rollover airbag and selected the saddle-shaped anti-rollover airbag for floating and immersion tests. The test results met expectations. The highest point of the contact point between the float and the aircraft was the lowest point of the cabin door. The points did not interfere in the vertical direction, and this method was finally chosen to be applied to the buoy to suppress the upturn of the buoy.
Numerical simulation of the effect of helicopter flight advance ratio and lift rate on rotor aerodynamic noise
Authors: Huang Surui , Sun Chengyuan , Yang Yaodong , Chen Hongchang , Yang Kai 
Published: May 2024

Abstract
To study the aerodynamic noise characteristics of helicopter rotors under different flight states, this paper combined with the FW-H calculation equation, adopted NACA0012 airfoil and ROBIN fuselage to form a helicopter model and used FLUENT software to simulate different flight states of the helicopter. The influence of the two flight parameters, advance ratios, and lift rates, on the aerodynamic noise characteristics of the rotor, is studied. The results show that with the increase of helicopter advance ratio, the aerodynamic noise generated by the rotor becomes larger, and the effect of helicopter lift rate on the aerodynamic noise of the rotor is not obvious.
Research on the mechanism of thermal-mechanical coupling effects of hypersonic aircraft rudder structure
Authors: Chen Hao , Zhang Yongli , Li Xiaopeng , Song Yiqiao 
Published: May 2024

Abstract
Hypersonic aircraft have achieved rapid development in the past decade, with flight speeds exceeding 5 Ma, posing a very severe aerodynamic and thermal environment for rudder structure. Especially for metal rudder wings, the extremely high temperature and temperature gradient makes the structural thermal response problem very prominent and complex. This article focuses on the study of the thermo-mechanical coupling response of the metal rudder wings of hypersonic aircraft in flight thermal environments. By simplifying the aerodynamic load and aerodynamic thermal environment under flight time sequence, a finite element model based on thermo-mechanical sequence coupling is established. The temperature, thermal stress, and deformation response curves of key parts are extracted, and the thermo-mechanical coupling response law of the rudder structure is explored. Based on the mechanical properties of structural materials at different temperatures, the corresponding relationship between stress and residual strength of key parts during flight time is obtained, and the safety factor of key parts of the structure is given.
Research on the de-tumbling method of magnetic moment variation of two stars based on the tangential formation
Authors: Li Ke , Shi Yongkang , Liao Qian 
Published: May 2024

Abstract
High-speed space debris threatens the safety of satellites in orbit, making the efficient removal of this debris an increasingly unavoidable necessity. By exploring the non-contact de-tumbling method for high-speed rotating targets, a de-tumbling technique is proposed. This method relies on leveraging the differential magnetic moments of two satellites arranged in tangential formation. Two single-coil electromagnetic satellites form a uniform magnetic field at the rotating targets, forming a tangential collinear distribution. The de-tumbling method of the simultaneous change of the magnetic moment of two satellites and the change of magnetic moment of one satellite and the other satellite is explored, and the de-tumbling effect is compared through numerical simulation. The simulation results indicate that the de-tumbling effect of the latter method is superior. Additionally, there is minimal variation observed in the relative distance between servicing stars and between servicing stars and target stars throughout the de-tumbling process.
Fixed-wing UAV based on vortex lattice method modular technology research
Authors: Xiao Hua , Su Xiaodong , Wang Yuan 
Published: May 2024

Abstract
The so-called modularity refers to dividing the system into several modules from top to bottom, layer by layer when solving a complex problem with various properties reflecting its internal characteristics. The main driving force for the demand for UAV modular technology comes from the requirements of UAV large-scale industrialization for UAV generalization, serialization, application scenario richness, and economy. The modular design of UAV is based on standardized software and hardware interfaces to carry out UAV aerodynamic shape module design, modular design of airframe structure, modular design of application load, module design of flight control system, module design of power system, etc.
A rapid time-coordinated longitudinal guidance method for high-speed vehicle
Authors: Li Xi , Gao Feng , Ma Aojia , Guo Dong 
Published: May 2024

Abstract
Compared to the traditional method of adjusting flight time by increasing lateral maneuverability [1-2], a faster time-coordinated longitudinal guidance method for unpowered high-speed vehicles has been proposed in this paper. Firstly, the centroid dynamics model and flight constraint model of unpowered high-speed vehicles were established, and the angle of attack corridor was derived based on quasi-equilibrium gliding conditions (QEGC). Then, to plan a reasonable angle of attack profile, the flight capability of a single vehicle under different constant angles of attack is analyzed, including terminal altitude, terminal velocity, and terminal arrival time. Furthermore, to achieve a long-term high angle of attack flight, a rapid time-coordinated longitudinal guidance method based on a trapezoidal angle of attack profile was proposed. Finally, using the vehicle and its performance parameters from Chapter 3 [3], numerical simulations were conducted under nominal tasks and multi-vehicle collaborative tasks. The simulation results show that under different expected arrival times, this method can quickly plan the angle of attack profile that satisfies time constraints, with high computational efficiency. Moreover, the arrival time adjustment ability of this method is large, which can fully utilize the arrival time capability of the high-speed vehicle. The above research provides more convenient conditions for a collaborative flight of multiple vehicles.
Research on case-based reasoning for determining maintenance intervals of civil aircraft systems
Authors: Ye Siyuan 
Published: May 2024

Abstract
The development of a rational and effective maintenance program is an important way to keep the safety and the economy of the aircraft industry. The maintenance program indicates maintenance types and intervals of all components. As development maintenance types of the components are simple, interval is a key to developing the maintenance program. In this paper, Case-Based Reasoning (CBR) is introduced to determine the intervals of components. It focuses on the expression and adjustments of the case. Finally, the reliability data of components in Boeing 737 is taken as an example to certify this method. The results show that this method can determine the maintenance intervals effectively, and so it has important engineering application value.