Abstract:For the limit of the amount of design variables , It is difficulty to greatly improve the aerodynamic efficiency and the flight height and velocity adaptability of near-space propeller system, So the paper survey and analyze the foreign major research programs and principles on morphing propeller and rotor structures, trying to find a novel and breakthrough approach to increase significantly the efficiency and flight height and velocity adaptability of near-space propeller system. The study shows that the morphing structures have great potentialities.

Abstract:In the new century, the aviation market continues to strengthen the restrictive requirements such as energy , noise and others, the new generation civil aircraft has to make significant progress in aerodynamic drag reduction. Natural laminar low wing becomes a research hotspot.. This paper outlines the laminar technology classification, reviews the main research history of natural laminar flow, introduces the new progress of laminar flow in Europe TELFOLNA project and US ERA project which are ongoing, reviews the application of natural laminar flow wing and natural laminar flow nacelle, and analysis the problems of natural laminar flow wing in actual application. Laminar flow technology is one of the key technology for new generation aircraft development , natural laminar flow technology research is of great signification.

Abstract:With the performance improvement of aero-engine combustor, it becomes more and more important to cool the flame tube of combustor. The combustor with floating-wall can effectively reduce the wall heat stress and improve the force situation. The development process of flame tube cooling structure which including film cooling, multi-slant-hole cooling and laminates cooling were introduced, and their advantages and disadvantages were described. Then, the advanced technical characters of floating-wall such as development situation and key components are analyzed, the cooling type of impingement/effusion which based on floating-wall structure has a higher efficiency, it’s the type that been most widely used in advanced aero-engine combustor with floating-wall structure nowadays. Finally, the key technologies which include materials, manufacturing processes and characteristics of the cooling structure of floating-wall have been elaborated. The structure of floating-wall has a superior performance and broad prospect, so, the efficient cooling type is being widely used in the developing and pre-researching structure of aero-engine combustor.

Abstract:The visual comfort level of airplane flight deck has immediate impact on pilot. It’s bad for the health of the pilot and safe driving, which could cause visual fatigue and misoperation. So it has a great significance to provide comfortable visual environment for pilot inside airplane flight deck. Three indicators, namely, daylight glare probability (DGP), luminance ratios (LR) and vertical illuminance at the eye level (Ev) were used to analyse the optical simulation result in flight deck and study on the visual comfort under the different seasons, times, sky conditions, and the database about comfort was established. The result shows that this method can estimate the visual comfort of flight deck effectively in the stage of airplane design.

Abstract:Leading edge absorbing structure, which possesses both load bearing and wave absorption performances, is one of the important research topics on stealth structural design. In this paper, zero-order and first-order optimization algorithms are implemented for optimizing the load performance of a typical leading edge absorbing structure. The optimal configuration on transparent skin and absorbing filling is obtained. And the optimization Analysis method and technical approach are presented for improving the load efficiency of leading edge absorbing structure. This optimization analysis scheme is very valuable for stealth structural design.

Abstract:This paper uses longitudinal-lateral-torsional integrated beam model and coupled mass method to simulate load-bearing structure of rocket and liquid propellant, and also uses RBE2 element to simulate the joints between the core and the booster of launch vehicle. Different payload’s base frequency can be obtained by modifying the finite element model of payload. The author chooses four typical second states in the process of flying, and obtains the first ten natural frequency of the rocket in three different payload’s base frequency. Analysis shows that the integrated beam model is very simple and practical in analyzing the dynamic characteristics of rocket, and the results can meet the requirements. The model can be used for modal analysis at the early stage of design. At the same time, the effects of payload’s base frequency reduction on dynamic characteristics of rocket can be obtained by analyzing the natural frequency data. These conclusions can provide some basis to the designer of satellite.

Abstract:In order to reduce wing root bending moment of high aspect ratio unmanned vehicle, bi-fuselage and stay bar methods were used. The bending moment and deflection along the wings were calculated and analyzed. The results show that the two methods can greatly reduce the wing’s bending moment as well as deflection. Bi-fuselage’s reduction of moment can reach 24% of the original mono-fuselage and stay bar can reduce to 20%. The deflection reductions are significant too. The instability characteristics of the compressed wings with stay bars were analyzed and the result shows that the wings will not lose stability under the assuming parameter.

Abstract:In this article we lead different fundamental frequency to the launch vehicle’s longitudinal model.By changing the frequency, vehicle’s dynamic response analysis is analyzed with finite element method and calculate the acceleration/element force response on payload with the changing of jet thrust . It discovers that the fundamental frequency affects the dynamic response of the launch vehicle;The effect is more patency on payload than other parts;The smaller frequency is,the bigger acceleration response of payload.

Abstract:In order to capture the rear stages’ clearance effects of high pressure compressor with tandem stator, a redesign of a high-turning tandem cascade was studied in the manner of linear cascade with different clearance sizes. The cascade performances, tip loading and the development trajectory of leakage vortex were compared with collateral inlet boundary layer and skewed inlet boundary layer. The results show that the tip region blockage is burdened and total pressure loss is sharpened with the clearance increasing. With the skewed inlet boundary layer, the pressure loss is decreased to some extent, and with small clearance the blockage of low span is relieved dramatically. Two leakage vortexes are captured near the tip region with 2% span clearance, and the front blade’s leakage vortex will vanish in the passage. The effect of skewed inlet boundary layer prolongs the trajectory of front blade leakage vortex. With the clearance increasing, the roll-up point moves downstream.

Abstract:Mathematical model is an important technical foundation for aircraft engine performance simulation and control system design. According to the needs of civil turbofan engine modeling, take high bypass ratio turbofan engine as the research object, the structural features and component modeling methods of engine main components related to the whole engine modeling were analyzed. Combing foreign experience with theoretical analysis, the big fan component characteristic decomposing methods, structure and modeling methods of engine air bleed system, compressor stability control system,turbine blade tip clearance control system and thrust reverser device were investigated in detail. The research results can provide technical support for civil turbofan modeling.

Abstract:This paper focuses on the pressure coefficient distribution in simplified model of some realistic turbine blade internal cooling channel for obtaining the characteristic of outflow rate allocations influence on pressure coefficient distribution. This model has been amplified geometrically according to analogous theory. Experiments with five outflow rate allocations of these three outlets including outlet1, outlet2, and outlet3, have been performed based on inlet Reynold number from 27000~34000. The experimental results show that : (1). the pressure coefficient distribution in the first channel has not been influenced obviously by different outflow rate allocations, besides in the second and the third channel; (2). the pressure coefficient of this model will wholly decline when increasing outflow rate allocation of outlet2 and decreasing outflow rate allocation of outlet1 and outlet3; (3). the pressure coefficient of the third channel will be more higher than other situations and the declining trend of pressure coefficient will be more gently than others when the outflow rate allocation of outlet3 increases.

Abstract:The relations of the cascade aerodynamic state and the openings of the valves in short duration wind tunnel are studied, and the method to control the stabilization of the experiment state is discussed in detail. Using the calculated valves’ openings according to the valves’ discharge characteristic data, the required state can be reached with 1-2 debugging states. By combining the pressure regulating valve’s discharge characteristic data with the traditional PID, an effective method maintaining the cascade aerodynamic state during the experiment is given, which can automatically compute the control parameters and precisely control the cascade aerodynamic state. With the new method, small calculation time is needed, and stable pressure state can be achieved rapidly and monotonously. The method can be used for reference by other short duration wind tunnel.

Abstract:HUD (Head-up Display) is a flight support device which has been widely used in aircraft. Important information on the instruments could be observed by pilots without lower their heads. A 2D micro scanning mirror-based HUD is presented in this paper due to the shortcomings of conventional HUD such as great volume and high cost. Through analyzing the relationship among oscillation frequencies of 2D micro scanning mirror, resolution, refresh rate and stability of HUD pattern, a prototype of HUD has been built successfully to project a common symbol. The projected image proves the feasibility of 2D scanning mirror-based HUD.

Abstract:With the rapid development of technology in Unmanned Aerial Vehicles Ground Control Station (UAV GCS), the ergonomic assessment of UAV GCS becomes important and urgent, which could not only alleviate the workload of the UAV operator, but also avoid flight accident. The research presented in this paper analyses characters of ergonomic evaluations of Unmanned Aerial Vehicles Ground Control Station(UAV GCS), and borrows ideas from method for ergonomic assessment of piloted aircraft. The Delphi method is used to build the evaluation indexes for UAV GCS, and the expert questionnaire for ergonomic evaluation of UAV GCS is established, in the end the method and contend of ergonomic evaluations is also presented, which could be used as the guidance for ergonomic integration evaluations of UAV GCS.

Abstract:The application of plasma actuators for flow control is one of the most popular researches nowadays. By using numerical simulation, this paper mainly studied two things: the method of simulating the effect of plasma actuators on flow fields; the plasma control of airfoil separated flow at large angles of attack. In this paper, a simplified model for plasma actuators is presented using FLUENT UDF to numerically simulate the plasma control of NACA0015 airfoil at large angles of attack. The results show that DBD plasma actuators can delay flow separation, increase the lift, and decrease the drag of the airfoil. Based on the analysis of numerical results, this paper also discusses the effect of the location, number, and strength of plasma actuators on flow separation.

Abstract:According to the characteristics of rotor wing aircraft, the helicopterSflying platform is developed that can apply to rotor wing aircraft research. Structural design of rotor wing and power system is analyzed and the calculating and comparing of aerodynamic performance of elliptic airfoils with different thickness-chord ratio using numerical calculation method is given. And in the end of this paper, the calculation and experimental investigation of rotor wing in hover is developed, the results in this paper provides some reference value for the research of rotor wing aircraft.

Abstract:[Abstrac] In order to obtain the aerodynamic characteristic of the stratospheric airship for large attack angle ， Aerodynamic numerical simulation Analysis with condition of large attack angle of a stratospheric airship is accomplished in this paper based on N-S equations andκ-ωsst model. It has been found that there are big differences between the stratospheric airship and aircraft on large attack-angle stall characteristic and torque characteristic. The stall angle of the airship is higher （around 45°）and torque character presents entirely different trends before stall. It indicates that the airship is instability within small angle range, but stability when the angle increases to some extentand will keep the state until stall. The study result has some important reference value to large attack angle controllability and stability design as well as flight control design of stratospheric airship.

Abstract:Bird strikes cause hundred million dollars in damage to civilian and military aviation each year. In order to reduce the cost of validation tests and improve the efficiency of aircraft design, CAE technique is introduced to perform bird-strike analysis. A reliable FEM model is built up to simulate the bird-strike process on vertical tail LE structure of a certain type of aircraft in HyperMesh environment. SPH algorithm is employed since it is more efficient tracking of material deformations and history dependent behavior than Euler bird model. And a beam type spring element with failure model material is employed to simulate the riveted joints. The numerical result based on finite element coupling and SPH algorithm using LS-DYNA software indicates that the structure meets the requirement of the civil aviation regulation and that the method and the calculation model are reliable.

Abstract:The research of composite laminates after low-velocity impact compressive failure has important significance in composite structure design. According to the ASTM D 7136 and 7137 test standard, the low-velocity impact test and compressive test of CCF300/5228 laminate were conducted. Basing on the cumulative damage theory, a model which setted the damages obtained from the low-velocity impact numerical simulation as the initial damages was established to explore compression failure of composite laminates with low-velocity impact damage. In this model , the strain failure criterion was applied and the degradation of the material properties was considered. Finally, the damage evolution and residual compressive strength of CCF300/5228 laminates were studied by this model. The results showed that, this model can explain the failure phenomenon well during the experiment and predict the residual compressive strength of laminates accurately. And it’s proved that, the damage propagation and failure mode from the model agreed with the experimental results well.

Abstract:Numerical finite element modelling techniques and failure analysis methods for integrated composite joint interface were studied. Different modelling techniques and failure models were adopt for joint interfaces bearing different loadings. The rule for defining interface mechanical properties was prescribed based on comparison between test results and simulations. The research of this paper can provide engineering utilizable analysis method for integrated composite structure design and analysis.

Abstract:The number of fatigue test data is generally small, thus under the assumption of weibull distribution, the statistical confidence of characteristic life should be taken into consideration. In this paper, probability estimation methods of characteristic life are summarized, such as Bayesian method and Bootstrap method of virtually expanded sample. Then seven groups of fatigue test data for straight lugs are applied for comparison of these methods. Because EDF fitting methods can’t offer substantial guidance to the rationality of characteristic life’s estimations, a new method is proposed that all the test data should fall into (1- a) percentile interval of the life distribution. Through comparison and analysis, it can be concluded that estimations by Bayesian method are smaller than that of Bootstrap method, and the proposed judgment method is effective.

Abstract:The flap rail track is controlled track and geometric characteristics of flap, and it’s also an important input conditions of aircraft flap control rail mechanism. A new design method of fowler flap rail track is proposed, which according to the motion rule of fowler flap，the movement of the flap is simplified to a conical surface around a certain point outside the wingtip approximately, then the simulate functions of CATIA V5 are used to design the fowler flap rail track. In the end , the example of Y12F is given to show the effectiveness of this method.