Abstract:Trustvectoring nozzle can visibly enhance the maneuverability of aircraft. The applications of mechanical vectoringnozzle are limited due to the complicated structure and poor reliability, while the pneumatic vectoringnozzle has a better performance. Series of pneumatic vectoringnozzle are developed in recent years. The development of pneumaticvectorcontrol technology is introduced briefly. The research progress on the aerodynamic performance and configuration optimization of dual throat nozzle is reviewed in detail. Problems in existing research are summarized and the future developments of dual throat nozzle are prospected.

Abstract:The slipstream of the aircraft with four turbopropellers affects large area around the aircraft, and the induced variation of lift, drag, and pitching moment must be accurately measured to evaluate flight performance and quality. The aerodynamic force of the aircraft with slipstream effect is investigated quantitatively by powered wind tunnel tests, including the lift, drag, pitching moment and elevator efficiency characteristics. The wake flow field is measured by sevenhole probe technique. The research reveals that the lift and drag are increased due to the high speed slipstream, and the lift to drag ratio is reduced by 6% and 20% at typical cruise and climb condition respectively. The wake flow tests reveal that the slipstream sweeps from below the horizontal tail to above it with higher AOA(angle of attack), which causes the strongly nonlinear variation of pitching moment and elevator efficiency.

Abstract:For the importance of the aircraft antidamage ability assessment and the complex and fuzziness of the antidamage ability assessment, the assessment method of the aircraft antidamage ability based on adjacent important degree with entropy weight is proposed. The aircraft antidamage ability evaluation index system is built from four aspects of the sensitivity, vulnerability, the injuries to repair and combat capability, by using adjacent important degree and entropy weight to determine the subjective and objective weights. The antidamage ability evaluation model is presented according to the property of the evaluation indexes. Through the numerical example verification, it shows that this method is high maneuverability, high application value and easy to implement. The evaluation results are more objective, and the problems in the evaluation of the aircraft antidamage ability can be effectively solved.

Abstract:The research on the structure of T800 carbon fiber composite has just started in our country, so it is necessary to make a systematic study on the stability of stiffened panel with T800 carbon fiber reinforced composite. The test articles of 8 configurations are designed by varying the skin thickness, stiffener spacing, stiffener geometric parameters, and the compression stability tests are carried out. Considering the influence of the lateral boundary condition and the effective width of skin, two commonly used compression buckling load engineering calculation methods are verified. Results show that when the moment of inertia increases the buckling load will increase in the same stiffener area, the failure load of stiffened panels mainly depends on the cross sectional area of the panels, and the effect of skin thickness and stiffener spacing on buckling load is greater than that on failure load; For the thin skin, when the lateral simply supported and the effective width of skin is b=D-b2/2, the calculated value is closest to the experimental value; For the thick skin, when the lateral simply supported and the effective width of skin is b=D, the calculated value is closest to the experimental value.

Abstract:At present, the military electronics airborne equipment reliability test in China mainly depends on the traditional simulation test technology of reliability, which often shows the shortcomings of long test cycle, low efficiency, high cost and the susceptible experimental results accuracy. And through deteriorating of certain or some kind of stress in field, reliability intensifying test can quickly stimulate equipment design flaws and manufacturing process. A kind of suitable reliability intensifying test process is put forward, which provides the rules of implementation and requirements of the test stress level, load sequence, operation process, troubleshooting and etc. It is used in the engineering practice of a model project. Result shows that the test can significantly improve the reliability of equipment, and save the expenditure and time.

Abstract:In the busy airport capacity saturation phenomenon, closely spaced parallel runways implementing paired approach can effectively improve airport capacity, ease the airport runway congestion and flight delays. For ensuring safety operation of paired approach,the rear machine needs to be operated under reliable collision risk. In this paper, considering the track deflection caused by machine due to navigation error and human error, and on the basis of the situation that the front machine passes through the rear machine to approach the track, using the kinematic equation and gets paired into nearly two machine with vertical distance formula of deflection always changes, and using the Reich model launched a longitudinal collision risk assessment model, finally using MATLAB curves obtained the risk of collision with the relevant parameters, analysis of influence factors of the longitudinal collision risk.

Abstract:If the difference of the workload in a sector is too big, the airspace capacity will be limited, which will adversely affect the flight safety and airspace utilization. In order to improve the sector capacity, relieve air traffic pressure, the method of the Xi’an terminal sector capacity evaluation and optimization base on controller workload is constructed. Measuring the controller workload by the statistical analysis of the radar data, the comprehensive value of the controller workload, which accords with the Xi’an terminal workload, can be calculated. Then the Voronoi diagram is founded using computational geometry. According to the principle of balanced sector load regulation, and some actual constraints, applying genetic algorithm in terminal control airspace, the optimal design of sector structure can be achieved. Through sector optimization, the capacity of the terminal area of Xi’an is enhanced, the sectors of the control load is balanced, and good results are achieved. 

Abstract:As one of effective methods for antiradiation weapon against radar switching off, the passivelocation algorithm has been well studied. However, most passivelocation algorithm research has been undertaken based on the condition that antiradiation seekers work continuously. Accordingly, a passivelocation algorithm in view of discontinuous guidance for antiradiation UAV(unmanned aerial vehicle) is studied, and a method to solve the problem based on the Kalman filtering is proposed. Simulated results are presented to demonstrate the effectiveness of the method. Results show that this method can be used for unequal interval discontinuous guidance and it has certain location accuracy.

Abstract:There is a significant gustloads difference between the normal discretegust model and continuousturbulence model because of the strong lift nonlinearity of a low speed medium altitude long endurance(MALE) UAV. To solve this problem, an improved discretegust model is adopted, namely, the kinematic equation of gust load is solved and the nonlinear lift is also considered during the moving course. Result indicates that the gust load obtained by the improved method is smaller than that by normal discretegust model, and which is close to the actual gust load. At the same time, the gust load is accordance with that computed by continuousturbulence model.

Abstract:For transport category airplanes, postcrash fire is one of the important problems to be considered for cabin safety. The time for evacuation that delaying fire or flame into cabin, namely fuselage burnthrough resistance should be ensured. In this paper, the characteristics of postcrash fire, including the range of temperature, heat flux and influence factors are introduced, the process of fuselage burnthrough, accounting for the criterion of airworthiness regulation on fuselage burnthrough resistance are analyzed, the development of method of compliance to determine the burnthrough resistance is stated, and development tendency of fuselage burnthrough resistance in future is expected.

Abstract:In order to analyze the humidity effect on civil turbofan engine performance parameters, the humidity correction module for gas property and component characteristics are led into the engine based on components match method, and the simulation model of ambient humidity effect on civil turbofan engine is established. The humidity effect on engine thrust, spool speed and inlet mass flow are analyzed, and the correction curves are obtained. According to the humidity requirement stipulated in the airworthiness regulation of CCAR25, the humidity effect on 6 key operating conditions in the flight envelope is simulated. Results show that the engine will be affected most on the hot day takeoff, and the thrust will be decreased by 0.56 percent. In order to recuperate the thrust loss, the fan relative correct speed should be raised by 0.23 percent. The simulation results are compared with the humidity correction curves provided by the reference, and the same trend and similar order of magnitude verify the reliability of the simulation model.

Abstract:In order to improve the operating efficiency of closely spaced parallel runways, safe zones of paired approaches is analyzed. Combined with the relative motion relationship and speed characteristics of paired aircraft, paired approaches is divided into fast aircraft can not pass the slow aircraft pairing mode and fast aircraft beyond the slow aircraft pairing mode. Regarding the slow aircraft as the reference volume, the relative motion state of the fast is analyzed, and the safe area of the two pairing modes is given qualitatively. And then, taking account blunder, the model of collision-safety boundary is established. Meanwhile, considering the effect of the lead aircraft to the trailing because of side wind, the model of collisionsafety boundary is established. The model is verified by using the C class aircraft B737-800 and the D class of aircraft B747-400 as the paired aircraft on the base of relevant data of Hongqiao international airport. The results show that the proposed method can be used to quantitatively calculate the safe zones of the paired approaches in real time.

Abstract:The area control center(ACC) ensures the safety of the aircraft on route. The safety performance assessment can promote the improvement of the system security level. Through the analysis of the operation process of area control center and the influence factors of safety performance, the index system of safety performance assessment is established. The method combining the triangular fuzzy function and the analytic hierarchy process(AHP) is used to evaluate the index. Based on these, the integrated evaluation model of safety performance is established. The data of an area control center is used to verify the case. The result can reasonably reflect the safety management level of the area control center, which shows that the integrated evaluation model of safety performance is reasonable and can properly provide the decision basis for the safety management.

Abstract:The civil aero-engine inlet anti-icing system provide the guarantee to the engine operation safe in the icing condition. The Civil Aviation Administration of China published the regulation to the civil aeroengine operation in the icing condition. However, there is less relevant research work about anti-icing system design. In this paper, the research progress for inlet piccolo anti-icing system in recent years is introduces. The design requirement, design methods, optimization methods and test verification methods are described which provide a reference to the design of the civil aero-engine inlet piccolo anti-icing system.

Abstract:The quality of aircraft hydraulic transmission line system design is of direct influences on the performance of hydraulic system and user system. In order to form design guide, civil aircraft hydraulic transmission line system design is studied. According to the design thought of civil aircraft, start with requirements, the process and method of hydraulic transmission line system design for civil aircraft each development stage are summarized, including capture of input and output message, use of design method, achieve of design goals. It is very simple and effective to use pressure drop curves to distribute and adjust pressure drop and tubing size. The summarized design process and method in this paper can be a reference for hydraulic transmission line system design for civil aircraft.

Abstract:In a certain aircraft S-shaped inlet is used, which is of complex shape and high demands on the rigidity, assembly, inner surface quality and weight. It is needed to design such an inlet structure which meets all the demands. The inlet is designed by using the composites whole shaping and automatic tow laying technology. The development of the program and implementation methods are described in detail. It is made by finite element analysis and experimental verification. The results showed that the inlet structure meets the strength and stiffness requirements. Automatic tow laying technology can be effectively applied to variable cross section S-shaped inlet development. The results of the study could provides the basis for the development of other complex shape aircraft inlet.

Abstract:The non-normal operating procedures are the important basis for the operating crew to operate the airplane safely, and one of the most important factors to ensure the flight safety. The non-normal procedures involve many technical fields, so it takes long time to develop them and the development of the procedures is a complex system engineering. By analyzing the relevant international documents and reports, and according to the experience in the procedure development of the new type of airplane, the composition and function of the nonnormal operating procedures, the method of procedure confirmation, and the format of the procedures are introduced firstly. Then four stages of the non-normal operating procedures development, the contents of work at each stage and the personnel qualification are defined. Finally, the workflow of the non-normal operating procedures development is proved to be effective in operating the domestic new regional aircraft. It can be used as guidance for the non-normal operating procedures development by the civil airplane manufacturer.

Abstract:The military is pushing airworthiness examination in military aircraft development process to assure the security by drawing lessons from civil aircraft airworthiness management. Accordingly, aircraft development unit have to find out how to implement the requirements of airworthiness and integrate airworthiness with safety design. In this paper, the relationship between airworthiness and safety from the view of military aircraft design unit is explored and the similarities and differences between airworthiness work and safety work is compared. A proposal of how to combine airworthiness with safety management, design, evaluation and how to work efficiently is offered for an actual project. It can effectively avoid incoordination or even contradictory situation between the airworthiness work and safety design work. It can be the reference for the military airplane designers.