Abstract:Maximizing the utilization and benefit of airport resource has become a common goal of air transport stakeholders, including air navigation service providers, airports, airlines, passengers and governments. This work focuses on the development status and trends of airfield resource scheduling problem, which is part II of the whole research. The development status of airfield resource scheduling is discussed from the perspectives of evaluating the resource capability, improving the resource utilization, and planning the resource increment. Then, the development trends of integration, efficiency, intelligence, collaboration and greenization related to the research of airfield resource scheduling problem are analyzed. This paper is aimed to provide scientific guidances and references for the sustainable development of theory and practice in airport operation management.

Abstract:With the increase in demand for long-range rapid delivery of heavy equipment and materials such as missile launch vehicles, heavy tanks, and intelligent unmanned clusters, and the gradual maturity of penetrating counterair capabilities such as stealth fighters, long-range air-to-air missiles, and autonomous weapons beyond defense area, the existing conven-tional large-scale military transport aircraft will face great threats in terms of future battlefield requirements and survivabil-ity, the range of mobility/refueling/ early-warning will be severely squeezed. This paper first gives a brief overview of the current status of conventional large-scale military transport aircraft, then introduces the next generation of large-scale mili-tary transport aircraft and its key technologies developed by the United States and Russia, such as SACD, HWB, BWB and PAK TA. These pre-research programs and key technologies provide stealth transport/fueling/early-warning capabilities and even penetrating counterair capabilities for the next-generation large military transportation/tanker/early-warning air-craft. Finally, a brief analysis of aerodynamic layout and operation application trends of next generation large transporta-tion aircraft has been given, and an aerodynamics layout of HWB with TeDP has been proposed.

Abstract:Microporosities in casting alloys cannot be avoided in the casting process. They will destroy the continuity of matrix, cause stress concentration, become the crack source of fatigue failure, and reduce the fatigue life of structure greatly. The current progress of microprosity characteristics (size, shape and position) in casting alloys and their effects on fatigue life is reviewed and prospected in this paper. Most of the microporosities are casting porosities with irregular shape and rough inner wall, and they have great influence on fatigue life of casting alloy. The size characteristic of microporosities well follows the lognormal distribution and the maximum size can be a typical feature to evaluate the fatigue life. And shape characteristics follows the Weibull distribution, however the position characteristics is complex. It is hard to observe the maximum size porosity in large-size casings, so the statistical methods are always used to predict them, and the generalized Pareto distribution method can get the best prediction results. At present, the fatigue life prediction methods of casings with microporosities are not complete and the failure mechanism of microporosity is not clear, the quantitative prediction model of fatigue life needs to be further studied, which considers different characteristic parameters of porosities and the interaction between different porosities under complex loading.

Abstract:According to the design requirements related to high endurance factor, short take-off and landing , deforming resistance of MALE UAV, the investigation of the design methodology on multi-constraint of the two-element airfoil is conducted based upon the earlier studies of the one-element airfoil design. In this paper, the geometry of the two-element airfoil is generated with the method of controllable conic curves accompanied with the control points, and the parameters of control curves, slot and spin axis position are optimized using Genetic Algorithms. The results indicate that comparing to the ellipse cutting method, the present method using more control parameters is more flexible to the earlier airfoil and the pressure distributions is more reasonable. At the same time, the endurance factor, take-off lift and lift-to-drag ratio of the designed slot airfoil are improved substantially which satisfies the multi demands. This method in this paper is significant to the MALE UAV design.

Abstract:The flight mechanical model of tilt-rotor uav is the basis of designing flight control rate and analyzing flight characteristics. Based on the engineering reality, the nonlinear flight mechanics model of a new configuration tilt-rotor uav was set up. Features and advantages of the new type rotorcraft are analyzed compared with the traditional tilt-rotor. The flight dynamics model of helicopter model, conversion mode and airplane mode was developed. Based on the flight mechanics model, taking helicopter mode for example, trim and stability were analyzed for different flight speed. The calculate results show that, this configuration tilting rotor has good lateral and directional stability in helicopter mode; The lateral and longitudinal coupling of helicopter hover mode is very small.

Abstract:Abstract In the aircraft structure design, we need process two kinds of data. One is the data which have been discretized by the upstream specialty and provided in grid form, such as the aerodynamic loads on the Wing and the hatch, the inertia load of structure, fuel, equipment, payload and so on. The other is the data of load which acts in form of uninform or linear distribution such as pressure of pressured cabin or fuel tank. Aircraft structure applying distributed body force and distributed surface force are mainly composed of panels, frame webs and so on. Generally, they are simplified into triangular, rectangular and quadrilateral plane stress elements. In this paper, the equivalent nodal load shift processing algorithm of three kinds of typical units is studied according to the principle of energy equivalence, and the algorithm of discrete processing of distributed load is put forward, and the rationality of the processing method of the load moment component of the discard node in practical application is explained and verified. It is proved by an example that the proposed algorithm can be popularized and applied in practical engineering.

Abstract:Electronic Jamming is an important means to cover the penetration formation and improve survival probability of penetration aircraft when Air force performs ground penetrating mission. A compound interference method of jamming surface-to-air missile guidance radar by scattering long –range jamming signals though chaff clouds is proposed，which uses jammer to irradiate chaff clouds scattered on the penetration route, and injects jamming energy into the main lobe of surface-to-air missile guidance radar by scattering chaff clouds to make better interference effect. On basis of this method, a chaff projectile throwing model which can calculate Si effectively is proposed to guarantee the continuous and effective jamming to surface-to-air missile position when penetration formation carry out frontal penetration, It is proved through example that the model is reliable.

Abstract:In order to ensure that the trajectory parameters of fighter meet the throwing conditions of unguided bomb, an attack path planning method of fighter is proposed. In this method, a fighter movement model is first established, and a basic tactical action model library is generated, and the action combinations are combined into basic trajectories; then, an open-closed-loop control model of the action parameters in each stage is constructed to microscopically control the tactical actions, and in light of pilot"s experience the constraint range of the parameter change is determined. Finally, based on the basic performance of unguided bombs and the tactical application methods, the throwing parameters of fighter are limited, and the trajectory planning is completed. The simulation result for the mobile jump and dive attack tactics shows that the planned track satisfies the attack conditions and the movement parameters meet the flight requirements, thus verifying the feasibility and effectiveness of the method.

Abstract:Aiming at the lack of a set of scientific, systematically applied to aviation equipment, including aircraft, engines and missiles repair factory quality competitiveness evaluation system, using system engineering theory and process analysis method, from the quality system, quality support ability, operation ability and quality performance ability quality four aspects to build the covers, 60 tertiary index of 19 two class quality competitiveness evaluation index system. At the same time, an evaluation method based on the G1-expert combination of multiple relevant weights is proposed to comprehensively integrate the intention of decision makers or experts to form a set of standardized weight coefficients. Finally, according to the evaluation criteria, the repair factory was evaluated by experts and fuzzy evaluation, and further analysis was made. Through the pilot evaluation, the rationality of the index system and the feasibility of the evaluation method are verified, which has certain guiding and referential significance for the aviation repair plant to improve its quality competitiveness.

Abstract:Keep balance of cost and effective is an important condition for realizing the economic affordability of complex aircraft. The main methods of cost-effective equilibrium analysis are presented in the paper. The applicability of the theory and method of extenics in the cost-effective equilibrium analysis on large complex aircraft is proposed, including the overall architecture, matter-element model and application process. The introduction of a complex aircraft model example is constructed. Cost and performance indicator systems and test the feasibility of extenics and matter-element analysis. The study provides a theoretical reference for guaranteeing the economic affordability of large complex aircraft and promoting the optimization of life cycle cost-effectiveness management.

Abstract:In order to improve lift/drag of the tiltrotor aircraft in forward flight mode, the airfoil was optimized according to the flow velocity in front of the wing. Using NACA2412 as the original airfoil. Firstly, the airfoil parameterization was carried out by Hicks-Henne method and the design variables was determined; Isight integrated airfoil generation, mesh generation and flow field solver were used to build airfoil automatic optimization platform. Then, in order to improve the efficiency of optimization, a surrogate model based on Optimal Latin Hypercube Design (Opt LHD) and Radial Basis Function (RBF) was adopted, and multi-island genetic algorithm (MIGA) was used to optimize the airfoil. Finally, the optimized airfoil was used to generate wing and the aerodynamic characteristics was calculated. In order to illustrate the effectiveness of the optimization method used in this paper, two optimization results were compared according to the different boundary conditions. In order to reduce the computational complexity, the rotor was replaced by actuator disk with the use of momentum source method. The results show that the lift/drag of the wing was increased by 66.03% in the forward flight mode.

Abstract:Vertical take-off and landing (VTOL) aircraft not only has the ability of vertical take-off and landing like helicopter, but also be provided with high-speed cruise capability as traditional fixed-wing . Aircraft. VTOL is one of the hot spots of research in both military and civilian unmanned aerial vehicles. In this paper, a new layout, tilt-tandem wing and quadrotor of VTOL aircraft, is proposed to avoid the defects of .low aerodynamic efficiency and complicated tilting mechanism. Conceptual design and aerodynamics simulation also have been carried out. the aerodynamic characteristics of aircraft with the interference of propellers Further more, prototypes are made and experienced several flight tests validation. The flight tests validation shows that this layout can avoid the disadvantages of low efficiency propellers and complicated tilting mechanism,which is reliable and practical.

Abstract:The cockpit and inlet play an important role for aircraft stealth performance. In order to analyze the scattering characteristics of cockpit and inlet, four kinds electromagnetic models with different components were established. The influence of RCS curve distribution, response of pitch angle and frequency were studied with Physical Optics method and relative value based on RCS mean. The results show that the scattering distribution is not changed by the cockpit and inlet with consideration of stealth design, and their distributions characteristics are similar. When the pitch angle increases, the RCS relative means of model C and D in nose, rear and circumferential directions increase oscillatorily, and relative means in lateral direction oscillate, and the biggest relative mean of model D in rear direction is 25.1942 dB with the pitch angle of 5 degree. When the frequency increases, the RCS relative means of model C and D in nose, rear and circumferential directions decrease oscillatorily, relative means in lateral direction increase gradually, and the biggest relative mean of model D in rear direction is 22.5722 dB with the frequency of 1GHz. The influence of cockpit on electromagnetic scattering is weak, and the relative value in nose direction is between -2.4 to 1 dB; while the inlet has greater impact on electromagnetic scattering, and the relative value in nose direction is between 2 to 12 dB.

Abstract:Flutter widely happens on solar-powered aircrafts due to the slight stiffness and large deformation, so that it is significant to establish the dynamic model of solar-powered aircrafts and analyze the flutter characteristics. Based on an initial dynamic model of a 15 meters span solar-powered aircraft is firstly build, the reverse modeling is implemented by optimize the model stiffness according to the objective flutter speed. Then the flutter analysis is carried out and a complete method for flutter analysis of solar-powered aircrafts is developed. Utilizing this method for reverse modeling and flutter analysis of a long straight wing of a solar-powered aircraft, the wing spar stiffness is estimated according to the flutter speed object. In addition, it is shown that the flutter speed will increase by 29% as the wing torsional stiffness increases by 70%. The present method can be used for wing structure design of the 15 meters span solar-powered aircraft.

Abstract:The elastic-plastic constitutive function of 30CrMnSiA steel is presented based on the total theory of plasticity, and the low cycle fatigue life of 30CrMnSiA notched specimens is predicted by damage mechanics-finite element method. The results are compared with the corresponding experimental results. The results show that the elastic-plastic constitutive relation method based on the total elastic-plastic theory is reasonable, and the fatigue life prediction results basically meet the engineering requirements. The low cycle fatigue life prediction of 30CrMnSiA notched specimens can be carried out based on the damage mechanics method.

Abstract:The composite laminates have been widely used in aerospace structures. The problem of reinforcement of laminates with holes has also got a lot of attention. In this paper, the reinforcement technology of composite laminates with large holes is studied. Tensile and shear experiments have been finished on the laminates reinforced by bolt connection technology and intercalation technology. The mechanical properties of reinforced laminates are compared with the laminate without hole, and some useful results have been got. Finite element models of reinforced laminates have been set. The simulation results fit well with the experiment results. The position of maximum strain has been got from the simulation results and different reinforcement schemes are compared. The best one is the laminate reinforced by intercalation technology, which have the basic sequence of layers and a circular hole in the middle.

Abstract:A numerical analysis spherical airbag model with unilateral folds is constructed to explore the dynamic application characteristics of the folding spherical airbag. By simulating the process of airbag expansion, the dynamic characteristics of airbag expansion under different folding times and different inflating conditions are researched. The factors affecting the volume and internal pressure curves of the airbag during expansion are discussed by comparing the volume and internal pressure curves of the airbag during expansion. The results show that the more folding times on one side, the higher maximum internal pressure of the airbag. The maximum internal pressure bearing capacity of the airbag material should be considered when setting folding times of the airbag. Inflation rate and volume affects the stability of airbag expansion. Inflation rate mainly affects the initial stage of airbag expansion, while inflation volume mainly affects the free expansion stage after inflation.

Abstract:As a complex product with high and new technology, the economical design of aviation equipment is paid more and more attention.As a complex product of high and new technology, the economical design of aviation equipment has been paid more and more attention. How to control and reduce the life cycle cost as much as possible is the focus of aviation equipment research under the premise of meeting user demand. Through the life cycle cost control theory and method of research, summary of aviation equipment development of economy experience and lessons, combined with the characteristics of military industrial products for management in China, from the aspects of ideology, management and technology, study a set of suitable for China's aviation equipment at the design stage of the life cycle cost control strategy, and in the development of a certain aircraft pilot application, achieved good effect of controlling cost, validate the life cycle cost of multi-path the rationality and validity of the control strategy.