Abstract:For one of the main causes of vibration failure during transition mode , the rotor rub-impact is a problem. In order to carry out more effective assessment verification and analysis, the current research status and analysis of the gap domestic and abroad were sorted out form the aspects of friction test device, test technology and coating wear test verification. The analysis showed that there was a certain gap between the speed, feed rate and coating heating temperature at home and abroad. And combined with the real operating conditions of the engine, the future development direction was put forward from the airworthiness verification. The development technology and test method of its test device have important engineering guidance for engine fault diagnosis analysis and military/civil aviation engine sealing coating airworthiness validation technology.

Abstract:Air refueling technology to a certain extent reflects the strength of a country’s air force,and this technology has been widely concerned. the paper summarizes the development history of hard type air tanker. Then suggests a concept of generation about hard type air tanker. The typical feature of the first generation was that the bomber being used as the refitting platform, which limited by the payload of the carrier and only provided limited external fuel supply. The typical features of second generation were refitted on the transporter, the effective external oil supplywas increased, and the fuel for the high-speed receiver at that time was added. . The third generation had a certain transportation capacity, equipped with advanced hard refueling device system, and set up a special refueling operator. The fourth generation had a certain cargo transportation capacity and developed to soft and hard three-point refueling. It had an advanced hard refueling device system. The fuel dispenser directly observed the fuel receiver and operated in a comfortable environment.The fifth generation required soft and hard refueling capability, air receiving capability, cargo and personnel transportation and medical evacuation capability, command, control and communication capability, network center capability and high survivability. The key technologies, such as general layout design technology, structure and mechanism design technology, control system design technology, were extracted to provide technical support for future equipment reform.

Abstract:With the increasing worse environment for aero-engine, the challenges for thermophysical properties and thermostability were put out. This article introduced methods of thermal barrier coatings and the choices of material at present. Besides, up-to-date research of material for better thermophysical properties and better performance in CMAS resistance were discussed, which provided a direction for further research on TBCs.

Abstract:Agent-based combat modelling and simulation is an important method for UAV swarm surveillance effectiveness evaluation. The agent behaviour mechanisms and model structures in previous agent-based combat modelling and simulation studies are difficult to describe self-organized surveillance behaviours in complex mission scenarios. In this paper, taking a counter-piracy surveillance mission as an example, a combat modelling and simulation method oriented for swarm self-organized surveillance is proposed. By the hierarchical composite behaviour mechanism and the composable modular model structure, complex behaviours are described by the composition of simple behaviours, and the self-organized path planning and flight control are realized by the interaction of the pheromone map module and the path management module. Simulation experiments are conducted to demonstrate the feasibility of the proposed method, and compare the surveillance effectiveness with different path planning methods. The results show that, self-organized path planning is more adaptive to dynamic events interrupting surveillance. In large-area, long-duration and low-target-density area coverage surveillance missions, merely decreasing revisit intervals by improving path planning methods cannot significantly increase the probability of finding targets.

Abstract:The key factor of military aircraft flight safety has changing from technology reasons to human factors. Especially in the situations of carrier-based aircraft taking-off modes, flight conditions and visual environment, decreasing the flight accidents resulting from flight deck human factors has great importance to ensure the carrier-based aircraft finishing flight and fighting tasks and enhancing flight safety. The paper makes a study on human factor airworthiness regulations, US military standards, SAE standards, China standards and China military standards, and then gives the framework of human factor criterions on flight deck airworthiness design. Finally, according the development phases and characters of military aircraft, the paper gives a evaluation method of carrier-based aircraft flight deck human factors, which could provide a routine and a means for carrier-based aircraft flight deck design and verification.

Abstract:The thermal residual stress of C/SiC affects the service performance of the material. In order to explore the influence of initial defects on the thermal residual stress, the steady change temperature method and the finite element computational mechanics (FECM) method are used to determine the relationship with thermal residual stress and initial defects of plain weave C/SiC composites. The distribution characteristics of various initial defects of the material were measured and statistically analyzed by scanning electron microscopy (SEM) of the sample. The representative volume unit (RVE) and the fiber bundle RVE finite element model of the macroscopic material with initial defects were established to predict effective performance parameters and thermal residual stress of fiber bundle RVE, and obtain the quantitative relationship between various initial defects and thermal residual stress of macroscopic materials.

Abstract:Signal collected in flutter test with variable progression speed is usually non-stationary, both its frequency and amplitude changed over time, especially in the sub-critical state. The common non-stationary signal processing method, such as time-varying parameter modeling can hardly analyze nor track the mode of signal precisely under high non-stationary degree. Therefore, an adaptive particle filter method based on non-stationary degree is proposed. The tracking performance under high non-stationary degree of this method is verified by Simulation experiment data. The results suggest that method proposed in this thesis has better precision under high non-stationary degree when compared with original particle filter.

Abstract:Military activities are one of the important factors affecting the airspace capacity of the terminal area. In order to predict the airspace capacity more accurately, the restricted flight zone is proposed to represent the area affected by military activities, and the corresponding design method is given. Based on the theory of maximum flow and minimum cut, the terminal area capacity affected by military activities is calculated. This paper analyzes the characteristics and defects of traditional algorithms at home and abroad, combines the principle of genetic algorithm, and use the improved genetic algorithm to solve the bottleneck of terminal area capacity affected by military activities. This method effectively avoids the limitation of exponential increase of computation. The corresponding population generation method, encoding and decoding method, fitness calculation method and cross mutation method are designed in the algorithm. The effectiveness and feasibility of this method are proved by an example simulation.

Abstract:For facing severely aerodynamic and inner equipments’ heat environment, the preliminary design scheme of integrated thermal management system which determines the feasibility of aircraft design, needs to be rapidly simulated to judge its feasibility, in the aircraft design stage. The traditional 3D simulation method is time-consuming and hard to meet the needs of frequent iterations in this stage. The fast simulation platform of integrated thermal management system based on heat balance evaluation model with 1D heat transfering approximation and modularly packaging of heat source, heat transfer, thermal control and other simulation components, which can quickly form the thermal management program and take simulation, optimization or iteration. Example shows that building the simulation platform and completing calculation each only take a few hours and several minutes, so as to speed up the iteration speed of the thermal management system, and can form a better aircraft design scheme in the preliminary design stage.

Abstract:Due to the small distance between the inlet port and the propeller blade, the propeller slipstream has a great impact on inlet flow field. In order to study this impact, unsteady CFD Methods are used to simulate inlet aerodynamic performance under the influence of propeller slipstream. The results show that: in the state of on ground and takeoff, the exit total pressure recovery coefficient is higher with slipstream than without it while the exit total pressure recovery coefficient is lower with slipstream in cruise flight. The primary factors cause the difference lie in whether propeller in front of the inlet does work to the airflow. Besides,when the flow from side channel flow backwards into inlet, the propeller slipstream will increase the distortion factor of the flow at the exit. The reason is that the slipstream will cause perturbation to the inlet flow field as propellers sweep past the inlet periodically. Also, the propeller wake will flows into inlet periodically. Thus, both of the two reasons will reduce the uniformity of the flow field in the inlet.

Abstract:In this paper, the topology optimization method based on SINH interpolation model in structural mechanics is applied in the design process of heat conduction structure, and a new mathematical model of topology optimization of heat conduction structure is established. By comparing the two-dimensional and three-dimensional heat conduction examples with the SIMP model and the RAMP model, it is concluded that the SINH interpolation model used in this paper is more accurate than the SIMP interpolation model, and has fewer iteration steps than the RAMP interpolation model. Therefore, the model established in this paper can better solve the topology optimization design problem of heat conduction structure.

Abstract:The landing gear of the aircraft bears a large impact load during landing, which causes the internal gear of the landing gear to withstand high oil pressure and air pressure. This paper analyzes the internal pressure changes during the landing process. Firstly, based on the axial load of the buffer, the pressure formula of each cavity of the buffer is obtained. Secondly, the differential equation of landing gear landing motion is established by using the two Mass System. Finally, the landing gear buffer pressure simulation model is built by using MATLAB/Simulink. The model is used to analyze the variation of the pressure of each chamber with time and buffer stroke at different landing speeds. The influence of oil chamber pressure on the cushioning performance with different oil return areas is also analyzed. The conclusion is as follows: at different landing speeds, the pressure of each cavity presents a certain regularity at a specific moment of the landing process; the positive stroke oil return hole should not be too small, ensuring that the oil fills the oil return cavity, and the reverse stroke oil return hole cannot be too Large to ensure that the oil fills the main oil chamber；The oil pressure in the buffer during landing impact affect the stability of the plunger.

Abstract:It is well known that the fuselage and wing mainly consist of thin-skin stiffened panels and the failure load of stiffened panels is hot topic in aircraft engineering. Johnson-Euler equation is used to evaluate the failure loads, thus the effective width of skin needs to be determined. As for effective width of skin, there are several kinds of methods to calculate it so far. So this paper will focus on the calculation of effective width of skin, and quest for it's origin. Finally, the applicability of calculating methods is validated by test results，which is shown the calculation errors are less than 10 percent for the thin-skin stiffened panels. The results of the paper will be beneficial to engineers who design thin- skin stiffened panels in compression.

Abstract:With the deep development of baseline spectrum or severe spectrum, it is becoming more urgent that how to develop a load spectrum and how to determine the fatigue life scatter factor when the measured data is used to develop the load spectrum. Based on the normal distribution theory, this paper discusses the factors that affect the dispersion of fatigue life, especially the difference between the baseline spectrum and the severe spectrum, and then proposes an idea and a method of the conversion of the baseline spectrum to the severe spectrum. The spectrum conversion factor is calculated and compared by the baseline spectrum and the severe spectrum developed by some measured data. The results show that both spectra can be converted to obtain the value of dispersion coefficient.

Abstract:Based on the construction of the laboratory climate test quality management system, combining with the technical requirements and characteristics of the laboratory climate test project, this article proposes a quality control model for aircraft laboratory climate experiment for the civil aircraft laboratory climate test of China according to the analyse and research on the content of relevant clauses and manufacturing compliance inspection requirements of Aircraft Type Certification Procedure. After the first key civil aircraft model laboratory climate environment test in China, including 10 low temperature subjects and 3 damp heat subjects, to assess the function and performance evaluation of the 8 types of structures or sub-systems of the 3 major systems under climatic conditions, the whole life cycle of the test project had no quality problems. The validity, adequacy and conformity of the model are proved, which provides practical support for the follow-up intervention model verification test of the bureau and provides quality assurance for the development of scientific research technology in China's laboratory climate environment test.

Abstract:Large-scale aerial refueling is complex system engineering, and the influencing factors are closely related to the tanker and the receiver. Due to the special layout of single wing, large wingspan, high vertical tail and large landing gear fairing on the large tanker (soft refueling), the aerodynamic interference between tanker, hose cone sleeve and tanker becomes very complicated during the process of refueling docking in air formation. By analyzing the main characteristics of domestic and foreign large-scale refueling and advanced refueling aircraft, this paper summarizes the aerodynamic interference between refueling and refueling aircraft in the process of air refueling docking, deeply studies the typical system of large-scale air refueling and refueling formation and the procedures of air refueling and refueling formation, and puts forward the possible safety pairs for large-scale air refueling and refueling. The validation factors of the impact of docking control are analyzed, and the docking safety design method of large-scale aerial refueling formation flight is given.

Abstract:A brief summarization is made about the airworthiness regulations of windshield heating system. Based on the related aircraft, the heat transfer processes simulation of windshield which is made of multilayer structures is predicted and characteristics of two different heating modes are analyzed. The results demonstrate that the Full Heating Power Mode could make a high heating rate and then the windshield will remain a higher temperature, which is good for performance of anti-ice and defogging. Duty Ratio Heating Mode could greatly reduce the thermal shock to windshield, but it also will produce significant impact on upstream equipment because of frequent change of heating power. This article explained the airworthiness regulations was explained and the key point of the requirement on design of windshield heating system is provided for the reference of system design and airworthiness certification.

Abstract:The Flap system is the significant system, and the flap electronic control unit is the core component. The double-V development process of SAE ARP4754A based on the requirements is the standard which is should followed by the civil aircraft. The research focuses on the flap electronic control unit is the core component, on the beginning, the design inputs in terms of function requirements， performance requirements and interface requirements are explained；Then, the paper surmises the Flap system architecture and working principle for civil aircraft, analyses the control logic for system's normal working and fault protection, uses Simulink to model and simulate, and build user interface by GUI. This study can be provide as a reference for the civil aircraft Flap control system design.

Abstract:Abstract: In order to improve the visibility and ease of operation of the aircraft cockpit display control system, based on reading a large number of relevant literature at home and abroad, and integrating the research progress of the aircraft cockpit display-control interface in recent years, this paper creates an aircraft cockpit display / Control interface design method. The design method is integrated in the C ++ system, and the pilot's three-dimensional geometric model and kinematics model are introduced at each stage of the aircraft cockpit design. Then, combined with the visual simulation modeling theory and related software, the flight vision and cockpit display are realized The development of the control interface; finally, the comprehensive evaluation method of the design of the aircraft cabin display control interface, the screening of various evaluation indicators and the establishment of the evaluation system are analyzed in detail, and some key technologies involved in the software design are discussed. The design method in this paper can finally simulate the pilot's operation movements and calculation parameters such as viewing angle, accessibility, and control force, which better reflect the pilot's kinematics and dynamics, which is convenient for improving the interface friendliness, intuitive operation, Simplicity, at the same time, it enriches designers' evaluation methods for aircraft cockpit design, ensuring design efficiency and accuracy; it is conducive to the improvement of aircraft cockpit design.

Abstract:Safe and efficient land-air communication is an important means to improve flight safety. It is necessary to comprehensively evaluate the functions, perfomace and system safety of the new intelligent system in order to use artificial intelligence technology to replace the function of flight crew. This paper designs the detailed operation process of the artificial intelligence flight communication system and the interoperation interface of the avionics system, and then develops the working principle and architecture of the artificial intelligence flight communication system, as well as the hardware implementation scheme and some pilot operational procedures. Based on the analysis of system safety and communication performance, it is concluded that the AI flight communicator is feasible and its performance is better than the original system.