Abstract:Supersonic inlet provides adequate and stable flow. The engine works more efficiently when the inlet performs more stably. However, the shock / boundary layer interaction severely impairs the aerodynamic performance and stability margin of the supersonic inlet. In the past 50 years, as one of the efficiency ways of active control, bleeding has been widely used to control the supersonic inlet flow for better performance and stability. While reviewing researches on supersonic inlet with bleeding from bleeding for boundary layer control and stable flow control, the author discusses the control mechanism of the shock / boundary layer interaction by bleeding and its influence on stability. The results also highlight the trend of the application of supersonic inlet with bleeding.

Abstract:With the increasing use of large composite components in aircraft structure,the huge effect on the mechanical performance of the composite structure when cutouts are localized on the composite laminate should draw researcher＇s attention and it is extremely urgent that the reinforcement concerned the cutouts should be investigated. This paper is focus on the research efforts over the past decade,the recent advance in mechanical behavior of the composite structure settled a cutout consist of stress concentration around the margin of cutout﹑the stability and failure behavior of the composite laminate is reviewed systematacially,incorporating the reinforcement strategies. Furthermore, several constructive suggestions are proposed with respect to research and designing on composite structure with cutouts.

Abstract:To perform a analysis of fire protection as defined in CCAR25 airworhtiness requirements of powerplant compartment, and to compare with the requirements in fire-proof and fire-resistent，we study the principia of the fire protection referred to the FAA Advisory Circular and Amendment, so that we can specified the fire-proof and fire-resistent requirments of the materials, parts and components in the powerplant com partment

Abstract:Morphing aircraft of telescoping wing can change wing area and aspect ratio by a variable-span morphing wing ,also change wing configuration and aerodynamic characteristics,which accommodate multiple flight conditions. This paper introduces in brief the development history of morphing aircraft of telescoping wing,and mainly explores the aerodynamic characteristics of a supersonic air vehicle with the concept of telescoping wing．The results of the analysis demonstrate an improvement in the aerodynamic characteristics of the morphing aircraft of telescoping wing．Wing span extension in subsonic represents a increase in aspect ratio and enhance the lift-drag ratio,in the form of a reduction in the induced drag,resulting in an increase in range．The wing span contraction represents a reduction in the aspect ratio and cut down the wave drag in supersonic,resulting in an increase in lift-drag ratio and improvement of flight performance of supersonic．Telescopic wing can take good consideration of both subsonic cruise and supersonic speed in supersonic aircraft design.

Abstract:The key of the computational accuracy, when calculating the aerodynamics of hypersonic by engineering methods, is the strategy for grid generation and the option of engineering methods. In this paper, a utility and easy-to-use method of grid generation is used, which allows each component of the model to use different computational method respectively; two order shock expansion method based on the approximate streamline fitting for many kinds of components with higher accuracy and less dependence on the experience of users is first introduced; when adding shock angle calculation in the two order shock expansion method, shock position of the model can be predicted; Spalding-Chi method based on initial surface element correct can supply more accurate viscous force coefficient compared with temperature reference method. The four cases indicate that, present methods have more accurate solutions when calculating aerodynamics of hypersonic, which can be used for preliminary design of hypersonic aircraft.

Abstract:The research destination of this paper is for fuselage’s stealth design, comparing three canonical sections’ stealth performance and the result can provide support for aircraft’s shape stealth design. Three typical stealth fuselage sections (concave, convex and plane-curve) are designed and the radar cross section (RCS) and the surface current are calculated with 2-dimensional method of moments (MoM). The characteristics of RCS's variance versus the aspect angle are analyzed and the stealth performances of the sections are compared via the overall and critical angle domain's RCS averages. The analysis results show that concave and convex fuselage can reduce side RCS and the convex's stealth performance is better. Plane-curve fuselage's side and down's RCS is small except for a narrow peak right in the down direction and this fuselage has good stealth performance in countering up-looking radar.

Abstract:The atmospheric sensor is important measuring instrument to get external atmospheric parameters of the plane. Parameters include: temperature, Angle of attack, total pressure and total temperature, etc. For civil aircraft in flight safety is the first. If the precision of atmospheric sensor is not enough or arranged unreasonably, it would cause risk during the flight. The purpose of this article is mainly to verify the scheme of atmospheric sensor’s layout, to get the optimized schemes and the belt where the static pressure of the nose is constant. Simultaneously the way of verifying the layout of atmospheric sensors is to be constituted. The results of aerodynamic characteristics of atmospheric sensors are gained by the low speed wind tunnel test and scaled sensors (wind vane and seven-hole probe).It indicates that the layout is important to the results of the atmospheric sensors; The experimental results is agreed well with the calculated and satisfied with the requirement of the aerodynamic.

Abstract:In order to improve the measurement accuracy of welding residual stress, welding residual stress is corrected by using shape-changed strength ratio and the method of discretizing joint material property on the base of residual stress test of 2219-T87 aluminum alloy TIG welding joint. Simultaneously, the effects of plastic deformation around holes and joint strength mismatch on welding residual stress estimation are studied separately. The results show that the method of estimating welding residual stress which considers both plastic deformation around hole and joint strength mismatch can reduce 39.8% error through contrasting with linear elastic estimation method; The way of considering the effect of joint strength mismatch and plastic deformation can reduce 40.6% error when the distance between the measuring point and welding seam is less than 8mm; And the joint strength mismatch effect on welding residual stress estimation can be ignored when the distance between the measuring point and welding seam is more than 8mm.

Abstract:Aimed for designing much light weight disk with enough strength, after the researches on aero-engine Bladed ring（Bling）in home and abroad have been summarized, mathematical model of light weight structure optimization design for fiber reinforced bling was put forward and established. Based on ANSYS optimization platform, under given load on the ring, parameterization model of structure optimization design for meridian plane of ring was established. Main optimum design variables of meridian plane were chosen, and design constraint conditions of fiber reinforced ring structural optimization were extended and established based on structural design criterion of metal disc. Through structure optimum design of typical fiber reinforced bling, lighter weight ring satisfying all strength constraint was obtained. It is found that the designed ring reinforced by SiC fiber could save 39.92% weight over the corresponding disk under same load, which illustrate that bling is of obviously advantage in weight saving, and the structure optimization design method of the fiber reinforced bling in this paper is effective.

Abstract:To solve the problem of advanced combustor liner wall thermal protection, numerical simulation was conducted to study the rhomboid-arrangement effusion cooling，and put forward a method to deal with the grid of rhomboid-arrangement effusion cooling. The liner wall temperature distribution was studied by liquid-solid coupling method, and the calculation of performance for the model combustor was performed by the standard k-ε Model and Non-Premixed (PDF) Combustion Model. The result showed that at the 0.046 fuel-air condition, the rhomboid-arrangement effusion cooling performed better than the alignment, the maximum wall temperature was 806K and the maximum temperature gradient was 20.7K/cm in working condition 1, the maximum wall temperature was 780K and the maximum temperature gradient was 34.4K/cm in working condition 2, which meets the need of wall temperature level for the advanced combustions at high fuel-air ratio.

Abstract:Analyze the bushing swage housing during airplane assembly process, Define the process purpose and qualified condition from design and manufacture aspect separately. Expatiated on the operational principle of swage housing and the selection of process method. Made a detailed analysis on the key factors of affecting swage housing quality, Such as the part’s fatigue strength and intensify on all the surface, The research result is of certain reference value for the condition of out of tolerance , meantime also demonstrate that the process can enhance the fatigue strength and resistant to corrosion ,and achieve the best condition for the bushing and hole.

Abstract:Some waviness of aircraft surface in special area will seriously affect the aerodynamic characteristics and flight performance. The waviness of these special area need to be measured accurately in order to analyze the affection and to get reference for manufacturing technology improvement. In this paper, a new analysis method of aircraft surface waviness was proposed, which is based on the 3D measurment technology. In the method, the Max/Exa-scan system was used to get the surface information of an actual aircraft, then the analysis functions of CATIA were used to analyze the waviness of measured area. In the end, an example was given to show the feasiblity and effectiveness of this method.

Abstract:Flight crew operating procedures, which are the basis of performing flight deck operational tasks for pilots, have played an important role in the airplane safety flight. Considering the research production of flight deck operations in civil aviation field and relating to the actual engineering experience, a general process

Abstract:A series of experiments on acoustic excitation on a multi-element airfoil performance were conducted in NF-3 wind tunnel in 2008. The results showed that internal acoustic excitation can change the aerodynamics characteristics of the airfoil under some conditions. This paper provides a computational method,which uses an assumption that turbulent kinetic energy can be a good analogy of acoustic excitation in study the effects of using internal acoustic excitation. Results of computation by solving 3D RANS are as follows:(1)The turbulent kinetic energy deduced lift in linear area of the airfoil by -2%(max) and improved lift around stall point by 5%(max);(2)The change on lift is smaller when the Reynolds number is higher;(3)When the O/L equals zero,the change on lift is the maximal one. These computational results are in good agreement with wind tunnel experiment in qualitative analysis. This paper confirms that the assumption of turbulent kinetic energy will be a nice expected approach to analogy of internal acoustic excitation.

Abstract:Infrared stealth is of great importance to increase the survival ability of the future aircraft. The exhaust system of the engine is the main source of infrared radiation at the tail hemisphere of the aircraft. In order to investigate the infrared radiation characteristics of the turbofan engines nozzle, a software for calculating the infrared radiation characteristics of the aero-engine exhaust system based on the discrete transfer method of infrared radiation numerical computation is developed, combining with mature CFD software. A ray-tracing method is proposed to improve the efficiency and precision of the calculation. Finally, the simulation of a baseline turbofan convergent nozzle and two improved nozzles with different infrared suppression measures is performed with the software. The results show that 2D nozzle can dramatically suppress infrared radiation of the nozzle in most orientation of detection while the infrared radiate intensity of ejector nozzle is less than the convergent nozzle at high azimuth angles and ray-tracing method is efficient and precise. The software developed can provide assistance for the design of exhaust nozzle with low infrared signal.

Abstract:Firstly, this paper analyzes functions and composition of the aircraft structural parts digital assembly system, and propose the four key technologies of digital assembly system. This article studies the assembly of the outer and the central wing from the measurement field construction, initial position calibration of the assembly system, assembly path planning, and measurement error compensation four aspects, and achieves the Posture Alignment and error measurement and control of the assembly system, completes the precision assembly of the outer and the central wing.