Abstract:Currently, engineering method is usually used to compute the load-carrying capacity of the panels in a design process. In this paper, three major engineering methods are briefly described and investigated. These methods are evaluated through the comparison of caculated results and test data, for the stiffed panels of the central wing and fuselage of an aircraft. It is shown that the results from ‘ultimate load method’ are safer and more consistent with the experimental data. The reasonable allowable stress for central wing of the aircraft is specified according to the previous comparisons and analysis. It is shown that this method can meet the requirement of an engineering design.

Abstract:In this paper the UAV close formation flight control problem is addressed. Formation flight involves controlling multiple wing aircraft to maintain a desired position relative to a lead aircraft throughout formation maneuvers. The formation consists of a lead and wing aircraft, where the wing flies in close formation with the lead, such that the lead’s vortices produce aerodynamic coupling effects. The nonlinear kinematic of formation was modeled in the wing’s Rotating reference frame. A proportional plus Integral controller is developed. It is shown that formation hold autopilots designed with the aerodynamic coupling effects ,yield satisfactory performance in close formation flight.

Abstract:This paper describe the principle of model-following and uncoupling，design the uncoupling control law by designing following loop and reference model .Through the simulation by using a aircraft model,analysis the affects,including the adjusting of parameters and serve loop,and then give a solution.It is concluded that this methd has obvious advantage and a certain value in engineering.

Abstract:Sublayer fence is one kind of wall shear stress sensors working through measuring the pressure between near-upstream and near-downstream of the fence submerged in the sublayer. So the relationship between wall shear stress and the corresponding pressure is its operational fundamental. However, there is no available mathematic model to describe the wall shear stress - pressure relationship so far. Here a method to establish the model was proposed. The method was then verified through comparing the established model with the experimental data of a developed divice. It showed good match between them in a wide range. A piezoresistive MEMS sublayer fence was designed and fabricated based on the method.

Abstract:Cockpit interior lighting, integrated displays, and other light-emitting display units have found increased application in the modern cockpit. As a result the optical environment within the cockpit becomes more complicated. Inappropriate lighting and furnishing design or cockpit spatial layout generates glare and affects flight safety. The present paper analyzes the effects of center pedestal Control Display Unit (CDU) orientation and position changes on resultant windshield glare. We find that, for curved windshield, CDU orientation has limited influence on glare distribution while CDU position has a pronounced impact on glare distribution. Hence changes in CDU position are effective in alleviating or eliminating glare.

Abstract:This article takes steering system of a certain Domestic plane as study objective, and makes simulation and analysis on steering system through the Virtual.lab and Imagine.lab software co-simulation analysis methods, and confirms the primary factor which affects maximum static steering torque of the landing gear amongst such factors as forward angle, wheel space, castor trails, tire vertical stiffness. Analysis result shows forward angle affects maximum static steering torque of the nose gear primarily.

Abstract:Time domain Neal-Smith ( TDNS ) criterion is originated from frequency domain Neal-Smith ( FDNS ) criterion and step target tracking criterion which has been widely used in the research on prediction of longitudinal PIO. In the closed loop system of this criterion, quasi-linear pilot model is extensively used because it has simple structure and can reflect the basic characteristics of pilot’s behavior. But in reality, the driver behavior is usually highly nonlinear, in order to describe the nonlinear characteristics more accurately, this paper uses neural network method to establish the pilot model. Taking a plane as an example, flight test data is used to train and test the neural network, and then creates a model of neural network. Based on time domain Neal-Smith ( TDNS ) criterion, the simulation model is established. Through computer simulation, the prediction results of the PIO trends are obtained. Research shows that compared with the traditional pilot model, neural network model can match with the real driver better. Therefore, putting neural network model into TDNS assessment criterion has actual significance.

Abstract:According to the requirements of “Airworthiness Standards: Transport Category Airplanes” by CAAC, the assessment on ditching floatation characteristics have to be provided to ensure the occupants can leave the airplane and enter the life-rafts. The regulation requirements, the method and procedure of model test for ditching floatation characteristics is introduced in this paper. The application result analysis is also presented .This is of important influence on the airworthiness certification of ditching floatation characteristics for transport category airplanes.

Abstract:To get known the influence on the RCS of front sector which is arisen by weak scatterers such as gaps of different width, stair heights and structure types including straight gaps and zigzag gaps, and to emphasize the importance of decreasing weak scatterers, the distributing status and characteristics of weak scattering sources like surface gaps and steps on the conventional vehicle are introduced. The radar backscatter strength of the gap is theoretically analyzed. The low RCS carrier and RCS testing models are designed, on which certain RCS experiments of gaps with different width, stair heights and architectures are carried on. The test results indicates that in order to control the surface electromagnetic defects (SEMD) of stealthy vehicles, it should take some measures such as reducing gap width and step height, replacing straight gaps by zigzag gaps, etc, which are proved to be high-effective technology ways.