Search

At present,there are no relevant standards and specifications for the verification of civil aircraft maintenance manuals in China.It is urgent to carry out relevant research and establish a complete manual verification system as soon as possible.T his paper puts forward the technical requirements,operation process and implementation points of manual verification operation based on large number of maintenance manual verification work,which combined with the flight test modification work.Taking the aircraft maintenance manual verification procedure of flap high lift system and flap structural components as an example,this paper carries out the manual verification plan arrangement and verification implementation method design from the perspective of practical operation feasibility and time saving.The key elements of the verification plan and design of practical operation process are given.The key operate points and precautions for greater difficult flap removal and installation programs are given as example,and the summary of common maintenance problems and improvement methods are recommended.All these work put forward suggestions for the follow-up verification work.

Safety assessment on civil aircraft is one of the effective methods to realize the airworthiness of aircraft. Based on the principle and method of civil aircraft system safety design and assessment, a certain high lift system is taken as an example, and functional hazard analysis and fault tree analysis are carried out for the failure condition of 'flap asymmetry motion over limit', the critical factor affecting safety design are gained. By improving the design method of the critical factor, the system scheme which can meet the safety requirement is finally obtained. The results show that the system can meet the quantitative requirements of safety.

Magnetic gears are designed to perform in a highly reliable manner, and offer several advantages compared to mechanical gears but difficulties with manufacturing techniques and cost are strong handicaps. In contrast to conventional gears, the contact and lubrication free force transmitting elements lead to a considerable lifetime and range extension of drive systems. In recent years, magnetic gears have been extensively researched and discussed by both academics and engineers from different industries. However, the vast majority of published work on magnetic gearing relates to novel topologies and performance improvement but not on optimisation of cost and weight. With a judicious parametric model analysis, design can be optimised in terms of torque capability, cost and weight. Moreover, the design process is time and cost consuming, but can be also be reduced by the use of modelling methods. An earlier paper addressed the parametric model approach and its benefits, but did not include a comparison between test and simulation data. This study will summarise the findings and present the test data from a magnetic gearbox designed for an aerospace application such as a high lift system.

The flap lift device is an important part of the conventional configuration of aircrafts and has an important impact on the aerodynamic performance. In this paper, a high-efficiency, simple, and energy-saving nanosecond dielectric barrier discharge (DBD) plasma actuator is placed in the vicinity of the flap lift device to improve the aerodynamic performance of the flap by controlling the flow field. The two-dimensional airfoil GAW-1 and its 29% flap were selected as the research objects, and the nanosecond (NS) DBD actuators were fixed at different locations near the deflection angle of the 10°flap. The excitation frequency, pulse width, and energy density parameters of the pulse discharge were adjusted, and then, the effects of parameter changes on aerodynamic characteristics of the airfoil were studied by numerical simulation. The simulation results show that adjusting the excitation frequency on the aerodynamic drag is weak and that the effect on the aerodynamic lift is obvious. The increase of the discharge pulse width will have a more significant effect on the flow field, i.e., a proper increase of the discharge pulse width can achieve better drag reduction, and increase lift after a stall at a high angle of attack. Although the increase of discharge energy density can strengthen the pulse perturbation effect on the flow field, it also contributes to some adverse effects and has no obvious optimization effect on the control efficiency of lift increase and drag reduction. [ABSTRACT FROM AUTHOR]

Magnetic gears are designed to perform in a highly reliable manner, and offer several advantages compared to mechanical gears but difficulties with manufacturing techniques and cost are strong handicaps. In contrast to conventional gears, the contact and lubrication free force transmitting elements lead to a considerable lifetime and range extension of drive systems. In recent years, magnetic gears have been extensively researched and discussed by both academics and engineers from different industries. However, the vast majority of published work on magnetic gearing relates to novel topologies and performance improvement but not on optimisation of cost and weight. With a judicious parametric model analysis, design can be optimised in terms of torque capability, cost and weight. Moreover, the design process is time and cost consuming, but can be also be reduced by the use of modelling methods. An earlier paper addressed the parametric model approach and its benefits, but did not include a comparison between test and simulation data. This study will summarise the findings and present the test data from a magnetic gearbox designed for an aerospace application such as a high lift system. [ABSTRACT FROM AUTHOR]

In this article presented the main result of numerical investigation of ability to improve the aerodynamic perfection of modern combat training aircraft. To determine the aerodynamic characteristic was used the discrete vortex method with closed vortex frames. In the work was presented the algorithm of a deflection of mechanization of a wing for increase of aerodynamic quality of the aircraft. The calculation of flight range and duration was at incremental extension and at realization of adaptive deflection of nose flap for Mach number M < 0.6.

This paper presents experimental results obtained with passive high lift systems using a combination of smart flap kinematics and vortex generators. A mid-scale 2.5D wind tunnel model based on DLR-F15 is tested in INCAS Subsonic Wind Tunnel, swept at 30 deg, incorporating the slat, 54 flap/VG/chord extension configurations and test matrix, developed by Dassault-Aviation. INCAS designed, manufactured and instrumented components to be added to the existing INCAS-F15 2D wind tunnel model. The test campaign was completed and results are presented.

Following the successful results of the test campaign on 2D configuration of the oscillatoryblowing system in the flap gap of the INCAS F15 wind tunnel model, extensive evaluation of the 2.5Deffects have been initiated in order to enable solid understanding of the fluidic integrationsmechanisms and to validate this technology at a higher TRL level. Initial experiments on 2Dconfiguration were based on work performed in AVERT EU FP6 project where the oscillatory flapgap blowing system was designed and tested on a INCAS F15 2D wing model. In 2.5D test cases thiswork has been extended so that the proposed system may be selected as a mature technology in theJTI Clean Sky, Smart Fixed Wing Aircraft ITD. New experimental setup was used and also updatedelectronics for the blowing system have been introduces. This was complemented by a new extensionfor the data acquisition system and visualization tools. Complex post-processing of the experimentaldata was mainly oriented towards system efficiency and TRL evaluation for this active technology.

For the problem that the flow separation on the flap lowers the aerodynamic performance of high lift system, an investigation was carried out on using micro vortex generators (VGs) to control the separation on flap of the swept constant chord half-model (SCCH) high-lift configuration, at a small to medium angle of attack, by experimental and numerical methods. The basic flow characteristics of SCCH landing configuration were analyzed by using numerical method to provide required information for the design of micro VGs. Then, by keeping the cruise configuration intact, the preliminary design procedure and design methods of micro VGs were established. In addition, the micro VGs were designed. The effects of VG's arrangement and geometric parameters, such as the arrangement mode, chordwise position, arrangement angle, height and spanwise distance, on controlling efficiency were investigated by using numerical method. Then the parameters of preliminary VGs were adjusted as the basis configuration for wind tunnel test. The experiments were accomplished in NH-2 wind tunnel for validating the numerical method, as well as obtaining the design principles and methods of micro VGs. The parameters of VGs were also optimized based on the experiments. The experimental results showed that the numerical design method can serve as an efficient and accurate design tool. The lift and drag were increased by 10% and 14%, respectively in landing state, which satisfied the requirements for landing. Finally, it was concluded that the established design principles and methods for micro VGs in this investigation can be used in engineering application. [ABSTRACT FROM AUTHOR]

In the framework of the European Research Program EUROLIFT (European High Lift Program), the ONERA experimental contribution is a basic experiment to study the transition phenomenon on a swept model equipped with a slat and a flap in high lift configuration. In preparation for the tests, the 3D high lift configuration has been computed at ONERA with a Navier Stokes code to get pressure distributions on the different elements. Preliminary transition prediction work was performed by different EUROLIFT partners (FOI, Airbus-D and ONERA), taking into account leading edge contamination and using the ONERA database method.The tests have been performed in the F1 ONERA low speed pressurised wind tunnel at two sweep angles and different Reynolds numbers. The model well equipped in pressure taps was completed by devices to determine the transition location (infrared thermography and hot films). The tests results have been analysed and the transition determined for all the elements, tested in the different configurations. Moreover we tried to analyse the transition behaviour under the Reynolds number influence in order to illustrate the different transition mechanisms found on this high lift generic model. [Copyright &y& Elsevier]