Abstract:Abstract: Wind energy is one of the mainstream types of renewable energy. At present, the majority of the traditional wind turbines could only make use of the near-earth wind energy. However, the high-altitude wind energy has a greater value and potential for its high stability and large storage of energy. The research of exploiting high-altitude wind energy is starting up in China while there are studies about the usage of high-altitude wind energy across the world and some were in the process of flight test. The research on the variation and development of the AWES is reported in this paper, which contains an analy-sis of Crosswind Mode, an introduction of worldly typical AWESs in last decade, a discussion of critical points including tether, accuracy control, multifunctional ground station and comprehensive optimization as a foundation for future development and further research on this direction.

Abstract:Air-to-air missile launcher which gives missile good separation attitude is an important mechanism of aircraft weapon system, it has a direct impact on combat capabilities of fighters. This paper summarized development process and present status of air-to-air missile launcher, focused on the theoretical research hotspot of the current mainstream launch mode of air-to-air missile such as guide rail, store ejection and embedded ejection , and pointed out that the high mach number launching, high overload launching, rolling launching, multidisciplinary coupling research of launching, ground ejection experiment technology considering pneumatic are still in initial stages, they are the focus of theoretical research in the future. Compared the two present classical embedded ejection launcher of stealth fighter, analyzed the key technology, technology advantages and disadvantages of them. In the end, technology development directions of air-air missile launcher was pointed out.

Abstract:The development about experiment of vibration and response for rotating blade with dry friction damper was summarized. Device , excitation method and dynamic characteristic method used in vibration test for rotating blade with dry friction damper were discussed emphatically , in order to provide technical support for test program, Improving structural reliability and efficiency, vibration reduction and lifetime extension. Experiment of vibration and response for rotating blade with dry friction damper were divided into two types：dynamic characteristic test based on loading the centrifugal force on the blade and damper, vibration stress measure based on blade and damper actuated by engine.According to present situation of experiment of vibration and response for rotating blade with dry friction damper,new research directions were suggested:establishment of test equipment model library,which according to the different tenon structure and angle of adjacent blade; exploring the coupling loading method for high frequency and measuring method of vibration response; investigation on excitation method more in line with real environment, developing the high idetifying measure method using the strain gauge and sensor.

Abstract:At present, with the rapid development of the civil aviation, air-ground communication is facing great challenge both from system capacity and from service quality. Accordingly, the current VHF communication system (AM-DSB、ACARS and VDL2) more and more can not meet the demand on the ATC traffic flow. As a result, a plan on B-VHF, which is an air-ground broad band technology, is recommended to solve the problem mentioned. B-VHF can realize overlay with current systems by OFDM modulation, taking use of the interspaces between working frequencies. It can improve both system capacity and service quality in coexistence with the current VHF system. In the paper, at first, we introduce the history of evolution of VHF air-ground communication in order to point out the reason why B-VHF concept is produced. Then, we analyze the framework￥procedure of B-VHF and discuss the principle from different views. Furthermore, we study the interference suppressing technology and spectrum sensing technology, aiming at realization of overlay with current systems. Finally, we prospect that B-VHF will be the mainstream of air-ground VHF communication in the future, and emphasize that it will be of great significance to carry out the research and experiment on B-VHF.

Abstract:Abstract：A statistical multiscale computation method based on the boundary element model is given to study the stationary heat conduction problem of functionally graded materials. Based on the characterization for microscopic configuration of functionally graded materials, which have continuous distributions of thermal properties over the entire structure by gradually changing the volume fractions of constituent materials, the multiscale boundary element model and statistical multiscale algorithm for computation of macroscopic equivalent parameters are brought forward. The validity of the proposed multiscale boundary element algorithm was verified by comparison with experimental results.

Abstract:The Magnus effect heavily affects the flight stability and trajectory calculation of the spinning projectile. A simple method based on rotating wall technique to calculate the effect of a rotating projectile with several planes of symmetry has been developed. Instead of using the dynamic mesh or multi-reference frame model, this method adds the rotating velocity to the surface of the projectile, and the Magnus force and moment can be obtained with steady calculations. The SOCBT configuration is used to testify the method. The calculation results are consistent with the experimental data in both static and rotating cases. Moreover, as the interference among the boundary layer, the separation flow at high angle of attack and the shock wave, enough gird nodes in boundary layer, as well as the calculating models, are needed to improve the precision of the Magnus effect simulation.

Abstract:Influenced by complex structure and poor working conditions, the working status of satellite will have abnormal state that between normal and fault, which would cause not only noise, but also abnormal data existed in the telemetry data. However, when the traditional data filtering algorithm is used to denoising, the abnormal data as well as the related information could be lost. Therefore, a combined filtering method of telemetry data based on double tree complex wavelet and morphological filtering is proposed in this paper. To be specific, a semi-soft threshold filter function is designed to improve the filtering performance. Thus, a combined filtering algorithm is proposed. The experimental results show that the proposed method can effectively filter the noise in the telemetry data and retain the abnormal data.

Abstract:Aiming at the optimum design of thick composite structure which is formed by repeating sub-laminates,?a multi-step optimization method is proposed in this paper. This method is composed of two steps. The first-step optimization design is conducted using the approximate model which is based on radial basis function neural network. The design variables include the number of plies in the sub-laminate and ply volume proportion. The second-step optimization is divided into two levels. The design variables of the system level are the number of sub-laminates, and the objective is to minimize the structural mass. The sub-system level is the optimization of laminate stacking sequence using genetic algorithm, and the objective is to minimize the inter-laminar stress factor. Matlab is adopted to program the genetic algorithm, and then integrated with Isight to carry out the whole optimization process. The case study shows that the multi-step optimization design method proposed in this paper is effective. The optimization method provides the idea for the initial design of thick composite structure and is of significant practical value in engineering.

Abstract:In order to ensure the reliability of the contact stress distribution on the hole boundary of the composite mechanical connection structure by the using of finite element method, this paper compared typical contact detection technology and contact constraints implementation technology in accuracy and applicability. The basic principles and characteristics of two contact detection technologies, including small sliding contact detection and finite sliding contact detection, and three contact constraints, including Lagrange multiplier method, direct constraint method and penalty function method are studied in detail. In order to validate the accuracy of different contact algorithms, the commercial finite element analysis software Nastran, Marc and Abaqus were utilized as stress analysis platform, and the numerical simulation results were carried out to compare with the test result of bolted joints composite laminate. The results indicated the finite sliding contact detection technology and penalty function method are more suitable for the finite element analysis of composite mechanical joints.

Abstract:The effects of input random variables’ uncertainties on failure probability can be characterized by failure probability based global sensitivity index, and they can provide guidance on how to reduce the failure probability of a structure. Based on support vector machine (SVM) method and monte-carlo (MCS) method, a new method is proposed for structural global sensitivity analysis in this study. Approximation model based on SVM is constructed to simulate the mapping relationship between input variables and output response, effectively overcome the issues of implicit limit state function and high computational effort. The uniform mapping, meanwhile, is employed to obtain a certain number of failure samples for a higher precision of approximation model. The approximate model based on SVM, under the small sample has good generalization ability, can significantly improve the computational efficiency, reducing the amount of calculation. Two numerical and an engineering examples are used to illustrate the accuracy and efficiency of the proposed method.

Abstract:Folding wing morphing aircraft can alter their shape largely which causes the aerodynamic parameters change significantly. So the aerodynamic effects caused by the asymmetric morphing can be used for aircraft maneuver control as an assist to the conventional control, which can enhance maneuvering flight ability. The purpose of this paper is studying the asymmetric morphing control efficiency of a folding wing morphing aircraft. Firstly, the nonlinear dynamic equations and aerodynamic model that can depict the full morphing process are derived. Then, an asymmetric morphing control model is proposed based on the asymmetric morphing control method. Finally, by comparing with the efficiency of conventional control and the dynamic response of simulation, we find the maximum effective interval of the asymmetric morphing control. The results show that the efficiency of asymmetric morphing control is higher at lower flight speeds, and the asymmetric morphing control can provide the highest roll handling efficiency near the reference folding angle of 90°.

Abstract:Continuous Trailing-Edge Flap has many advantages over conventional discrete flap in helicopter rotor vibration reduction applications, such as light weight, compact structure and stable airflow. MFC is used as the driving material, the blade section with continuous deformation trailing edge flap is designed based on the NACA23012 airfoil, and the material selection design of the profile structure is analyzed. The aerodynamic characteristics of the Continuous Trailing-Edge Flap is analyzed by Fluid-Structure Interaction method. The results show that the Continuous Trailing-Edge Flap can realize effective deflection in range of the helicopter blade working angle of attack, Mach number, and generate significant additional lift and torque increment. That demonstrates the potential value of Continuous Trailing-Edge Flap in rotor vibration damping application.

Abstract:For the low-wing configuration aircraft, server flow interference exist at the wing-body junction, the boundary layer stack at the junction is the main reason for flow separation, the flow separation result in drag addition. This paper focus on fairing and drag reduction, the fairings decrease the boundary layer thickness to the purpose of drag reduction by blowing away the boundary layer at the wing-body junction. Comparative analysis the characteristics of three different fairings, the numerical study and analyses indicates that the three different fairings achieve the fairing and drag reduction，improve the aerodynamic performance, can put a reference for fairing and drag reduction on the low-wing layout aircraft.

Abstract:Effectively decreasing induced drag can be significant for the aircraft to reduce the fuel consumption and increase the flight range. Numerical simulation with CFD methods were carried out to obtain the aerodynamic characteristics, especially the drag reduction effect of the fuselage and wing configuration with the fusion winglet. The results showed that tip vortex was decreased and drag coefficient was obviously reduced. The bending moment coefficient can be increased by 3.2% and drag coefficient can be decreased by 4.2% when specifying the lift coefficient to be 0.5.

Abstract:The aircraft shape could be changed by external equipment, thus the stealth performance could be also influenced. In order to study the variation trend and law of electromagnetic scattering characteristics with different angles and frequency, based on the electromagnetic models of aircraft with and without external equipment, the RCS curves of different frequencies and different pitch angles were simulated by the Physical Optics method. And RCS curves’ distribution characteristics and pitch angle characteristics of the two models were analyzed. The results showed that, in the angle domain on nose direction, the arithmetic mean values of the model without external store in different pitch angles appeared "W" type distribution, and the model with external store appeared inverted "V" distribution. The definition of RCS relative increment was proposed to analyze the influence of external equipment. The relative increments appeared "W" type distribution in angular domain on nose direction, and their values were about 10～25 dB. And the circumferential distribution of relative increments appeared oscillation, and the values were about 7 ~ 17 dB.

Abstract:To study tensile strength of composite laminates containing a central hole, this paper takes the composite laminates with a central hole as the research object. Tensile tests were conduct on specimens with three different ply ratio according to ASTM D5766 standard to study the influence of ply ratio on the tensile properties and failure modes on composite laminates. Based on continuum damage mechanics, the maximum strain criterion and no-linear Puck criterion which is physical-based were employed to predict the initiation of fiber and matrix damage respectively. The revolution of damage was based on strain on the fracture plane. Three dimensional finite element model of composite laminates with a central hole was built. The results of FEA model proved that the model can efficiently predict the tensile strength and damage revolution of composite laminates with a central hole.

Abstract:The major function of aircraft icing detection system was analyzed by FTA method. The FTA of icing detection system was built and simplified, and then the minimal cut sets were calculated and discussed here. According to qualitative results, the requirements of icing detection system on aircraft lever are suggested to avoid common cause Failures. The result analyzed by quantitative method is satisfied the requirement of icing detection system, which means the project of icing detection system is reasonable. The building and conclusion of FTA presented in this paper can be benefit for the icing detection system design．

Abstract:In order to ensure the flight safety of the aircraft, guarantee the bending fatigue durability of slat gear-rack mechanism in complicated working conditions, and Improve development efficiency, based on the analysis of aerodynamic loads, the virtual bending fatigue durability of slat gear-rack mechanism was analyzed used ANSYS and nCode. The effect of different surface roughness factors on bending fatigue life was analyzed. The results show that aerodynamic load is the main fatigue load during the working process of the slat gear-rack mechanism. The bending fatigue life of the slat gear-rack mechanism can be predicted under specific conditions. According to fatigue theory and virtual fatigue durability analysis, the integrated fatigue durability engineering method is applied to get the best design results, and the design cycle can be greatly shortened.

Abstract:Aviation gear reducer usually has high requirements for weight, strength, reliablity and efficiency. Considering the random characteristic of working conditions, the difference of technological level and the fluctuation of mechanical parameters such as material strength, the traditional deterministic parameter optimization design can not meet the needs of engineering practice. On the foundation of traditional deterministic optimization model, the multi-objective robust design optimization model of gear drive system is developed in this paper based on the basic theory of robust design of 6 sigma, and the Pareto solutions are obtained using NSGA-II multi-objective optimization algorithm. Subsequently, robust optimization for a single-stage helical gear system in an aviation gear reducer is carried out. The results show that the robust design model presented in this paper gives full consideration to the impact of uncertainty on optimization and has certain value for engineering application.

Abstract:With The rapid development of civil aircraft digital integrated collaborative development mode, the traditional airworthiness management system has become more and more unsuitable for the digitalization, informatization and networking of the collaborative development demand. It is urgent to establish a suitable airworthiness management system which can be adapted to collaborative development. This article obtains from the architecture of the collaborative development, analyzes the characteristics and the key technologies of the collaborative development, and then focuses on discussing the structure, feature and scope of the airworthiness management system based on the collaborative development mode. Finally, the construction scheme of the airworthiness-engineering collaborative management system for Type Certification process is given. This scheme can realize the airworthiness control for the whole aircraft development process, standardizes the airworthiness review activities, shortens the period of Type Certification, and then lay the foundation for the success of type development and commercial.