AVIC China Helicopter Research and Development Institute

Room, China

AVIC China Helicopter Research and Development Institute

Room, China
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CHENG X.,Beihang University | LI X.,Beihang University | ZHANG J.,Beihang University | ZHANG Q.,Beihang University | And 2 more authors.
Chinese Journal of Aeronautics | Year: 2017

Composite-metal joints with a metal insert are one kind of connecting structure. In this paper, tensile experimental tests were carried out to investigate tensile properties of a composite-metal joint with a novel metal insert design. Finite element models of the joint were established, and strain distribution and tensile strength were analyzed. The numerical results are in good agreement with the experimental results. Results show that the joint failure is dominated by shear properties of the resin layer. Increasing the resin layer thickness in a certain range will improve the tensile strength of the joint, while increasing the radius of the fillet on the ending side of the metal insert will decrease the joint strength. Increasing the resin layer plasticity will improve the joint strength. The effect of the embedded depth of the metal insert can be ignored. © 2017 Chinese Society of Aeronautics and Astronautics


Xu L.,Beihang University | Chen L.,Beihang University | Li X.,Beihang University | He T.,Avic China Helicopter Research and Development Institute
Applied Optics | Year: 2014

In this paper, we propose a projective rectification method for infrared images obtained from the measurement of temperature distribution on an air-cooled condenser (ACC) surface by using projection profile features and cross-ratio invariability. In the research, the infrared (IR) images acquired by the four IR cameras utilized are distorted to different degrees. To rectify the distorted IR images, the sizes of the acquired images are first enlarged by means of bicubic interpolation. Then, uniformly distributed control points are extracted in the enlarged images by constructing quadrangles with detected vertical lines and detected or constructed horizontal lines. The corresponding control points in the anticipated undistorted IR images are extracted by using projection profile features and cross-ratio invariability. Finally, a thirdorder polynomial rectification model is established and the coefficients of the model are computed with the mapping relationship between the control points in the distorted and anticipated undistorted images. Experimental results obtained from an industrial ACC unit show that the proposed method performs much better than any previous method we have adopted. Furthermore, all rectified images are stitched together to obtain a complete image of the whole ACC surface with a much higher spatial resolution than that obtained by using a single camera, which is not only useful but also necessary for more accurate and comprehensive analysis of ACC performance and more reliable optimization of ACC operations. © 2014 Optical Society of America.


Wu X.,AVIC China Helicopter Research and Development Institute
Nanjing Hangkong Hangtian Daxue Xuebao/Journal of Nanjing University of Aeronautics and Astronautics | Year: 2015

Based on the technology features and configuration characteristics, the high-speed rotorcraft can be classified as the compound helicopter, the tilt-rotor/wing rotorcraft, and the rotor/wing-interchanging rotorcraft. After studying the technology development of three categories of the high-speed rotorcraft, the developing direction and trend are analyzed. Furthermore, combined with the current status of high-speed rotorcraft in China, recommendations and measures are proposed to improve the development level of high-speed rotorcraft in China. © 2015, Editorial Department of Journal of NUAA. All right reserved.


Peng Y.,AVIC China Helicopter Research and Development Institute | Chen P.,AVIC China Helicopter Research and Development Institute | Sun Q.,AVIC China Helicopter Research and Development Institute
Nanjing Hangkong Hangtian Daxue Xuebao/Journal of Nanjing University of Aeronautics and Astronautics | Year: 2011

A mathematical model of the canted tail rotor is developed based on the blade element theory. UH-60A helicopter is taken as an example to carry out the trim calculation. The validation of the model s made by comparison between calculation results and flight test data, which indicates that the model of canted tail rotor is reasonable, accurate, and proper for the application n engineering. The effect of different canted angle on the required power of helicopter n hover is calculated, which concludes that the optimum canted angle of UH-60A s between 20° and 25°. The trim characteristics of helicopter in ever flight with canted tail rotor and conventional tail rotor are calculated and analyzed. The longitudinal trim of helicopter is changed when the tail rotor tilted up. Finally, the advantages and disadvantages of canted tail rotor are discussed.


Ma C.,AVIC China Helicopter Research and Development Institute | Wang Y.,AVIC China Helicopter Research and Development Institute | Li W.,AVIC China Helicopter Research and Development Institute
Lecture Notes in Electrical Engineering | Year: 2014

A flight data ground analysis system achieves the Flight Operational Quality Assurance (FOQA) and flight reproduction. Problems existed in the traditional method such as simple events characterization and not intuitive results. Based on the requirements analysis of the flight event investigation and troubleshooting, a new flight reproduction solution was presented, which integrated table, curve, 3D animation, cockpit view, and aeronautical chart view. Results show that the exceedance events can be positioned precisely, the flight can be reproduced accurately, the pilot's operation quality can be monitored, and flight safety can be guaranteed. © 2014 Springer-Verlag.


Cao Y.,AVIC China Helicopter Research and Development Institute | Fan F.,AVIC China Helicopter Research and Development Institute | Lin Y.,AVIC China Helicopter Research and Development Institute | Yuan M.,AVIC China Helicopter Research and Development Institute
Nanjing Hangkong Hangtian Daxue Xuebao/Journal of Nanjing University of Aeronautics and Astronautics | Year: 2016

For the comparison of sound level, experimental investigation on the aeroacoustic characteristics of three sets of model rotors under different tips with anhedral angles in hover is conducted in the anechoic chamber. The noise information on rotors at distinct collective pitch angles and observation points is collected. In aspect of numerical simulation, RANS control equations are solved to get the detailed flow-field aerodynamic information of rotor, and the aeroacoustic information is calculated based on FW-H equation. In the same conditions, test results and simulation results are in good agreement, which validates the feasibility of the presented numerical method. Finally, based upon the test results, comparisons of aeroacoustic characteristics among the model rotors with different blade tips are made. © 2016, Editorial Department of Journal of NUAA. All right reserved.


Xiong S.,AVIC China Helicopter Research and Development Institute | Jin K.,AVIC China Helicopter Research and Development Institute | Chen X.,AVIC China Helicopter Research and Development Institute
Nanjing Hangkong Hangtian Daxue Xuebao/Journal of Nanjing University of Aeronautics and Astronautics | Year: 2016

The material modulus is corrected based on the Halpin-Tsai formula according to the structure and deformation characteristics of composite flexbeam. The stiffness of flexbeam is calculated by the blade computer aided desigh (BCAD) special software except for the torsional stiffness which is calculated by the empirical formula. It is proved that the method can improve the calculation accuracy of the flexbeam section stiffness, and also can guarantee the accuracy of the dynamics and the lord calculation of bearingless rotor/tail rotor. © 2016, Editorial Department of Journal of NUAA. All right reserved.


Zhang S.,AVIC China Helicopter Research and Development Institute | Sun D.,AVIC China Helicopter Research and Development Institute | Liu X.,AVIC China Helicopter Research and Development Institute | Li M.,AVIC China Helicopter Research and Development Institute
Nanjing Hangkong Hangtian Daxue Xuebao/Journal of Nanjing University of Aeronautics and Astronautics | Year: 2016

The theoretical model of torsion-SARIB vibration isolation system is established, and the dynamic characteristics are analyzed by theory and simulation methods. The dynamics equations of plane torsion-SARIB are derived by the Lagrange method, and the spatial torsion-SARIB is simulated by the multi-body dynamics theory. The comparison between torsion-SARIB and cantilever beam SARIB indicates that torsion-SARIB has low space requirement and simple structure. The torsion-SARIB is more useful than the cantilever beam SARIB in the structure design. © 2016, Editorial Department of Journal of NUAA. All right reserved.


Sun W.,AVIC China Helicopter Research and Development Institute | Sun P.,AVIC China Helicopter Research and Development Institute | Lin Y.,AVIC China Helicopter Research and Development Institute
Nanjing Hangkong Hangtian Daxue Xuebao/Journal of Nanjing University of Aeronautics and Astronautics | Year: 2016

Firstly, the numerical simulations for the flow-field of typical urban area models are carried out by solving 3-D Navier-Stokes (N-S) equations based on viscous unstructured Cartesian grid. Secondly, the flow-field of typical urban area is measured by using the particle image velocimetry (PIV). Finally, comparisons between testing results and numerical calculation results are conducted to analyze the characteristics of typical urban area flow-field. © 2016, Editorial Department of Journal of NUAA. All right reserved.


Jin X.,AVIC China Helicopter Research and Development Institute | Li X.,AVIC China Helicopter Research and Development Institute | Chen H.,AVIC China Helicopter Research and Development Institute | Zhang X.,AVIC China Helicopter Research and Development Institute
Nanjing Hangkong Hangtian Daxue Xuebao/Journal of Nanjing University of Aeronautics and Astronautics | Year: 2016

To improve the helicopter safety better, the fault diagnosis of swash-plate bearing based on BP neural network and RBF neural network is investigated. Bearing seed fault tests are carried out, vibration data of bearing tests are obtained and its characteristic signals are collected. Some characteristic signals of vibration data are used as the inputs of neural networks to perform the fault diagnosis, and accurate fault diagnosis rates are obtained. The highest diagnosis rates of different kinds of bearing faults are high than 89%. © 2016, Editorial Department of Journal of NUAA. All right reserved.

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