AVIC The First Aircraft Institute
AVIC The First Aircraft Institute
Ren X.,AVIC The First Aircraft Institute |
Duan Z.,AVIC The First Aircraft Institute |
Wei J.,AVIC The First Aircraft Institute
Kongqi Donglixue Xuebao/Acta Aerodynamica Sinica | Year: 2017
A simple "body+wing+flap+nacelle+propeller+horizontal tail" model (Model A) and two modified ones (Model B and C) were simulated via commercial CFD codes, using unstructured surface matching grid and multi-frame of reference technique to solve Reynolds Averaged Navier-Stokes (RANS) equations. For the simulations, the whole computational domain was divided into three individual domains, namely two rotating domains for the propellers and one stationary domain. The slipstream effects at low speed and in high thrust coefficient condition were studied. It has been demonstrated that the pitching static stability of 'Model A' decreases sharply at low angles of attack, while increases slightly at high angles of attack due to the thrust generated by the propellers, the downwash effect of the wing and flap, and the interaction between the slipstream and horizontal tail (H-tail). Generally, the flow field around H-tail of a propeller-driven aircraft is affected by the general layout, the angle of attack, the downwash of the wing and flap, and the slipstream effect. More specifically, the downwash rate of the wing and flap increases due to the slipstream effect, while the efficiency of the H-tail decreases throughout the whole computed range of angles of attack. Since H-tail is not immersed in the slipstream, the high-energy fluid can hardly be utilized to increase its efficiency at low angles of attack. Moreover, it can be seen that the left H-tail contributes to the stability of 'Model A' due to the counter-clockwise rotation of the two propellers. In order to improve the efficiency of H-tail, designers are suggested to modify the relative position between H-tail and the propeller slipstream to make sure that H-tail can be surrounded by high-energy flow generated by the propeller. Moving up the propeller by 0.7 m (Model B) or moving down the H-tail by 0.86 m (Model C) has been proved as feasible modifications to increase the pitching static margin at low angles of attack. © 2017, The Editorial Board of ACTA AERODYNAMICA SINICA. All right reserved.
Yang C.,Beihang University |
Huang C.,Beihang University |
Wu Z.,Beihang University |
Tang C.,AVIC The First Aircraft Institute
Hangkong Xuebao/Acta Aeronautica et Astronautica Sinica | Year: 2015
The aeroservoelasticity (ASE) problems occurring on the aircraft (e.g. airplanes, missiles) originate from the sophisticated coupling between aerodynamics, structural elasticity and control system. As the aircraft develops to be lighter, faster and more capable, these problems become increasingly acute and thus have a direct influence on flight safety and performance. After more than sixty years of research, great progress has been made at home and abroad in the field of ASE analysis, synthesis and test. In the recent decade, several new issues are revealed due to the design evolution of aircraft with unconventional configuration, and pose the huge challenges to ASE research, which is worth analysis specifically. This paper discusses the problems of rigid/elastic interaction, nonlinearity, thrust vectoring and system identification in ASE analysis, and states the key issues for gust alleviation, active flutter suppression and ASE optimization in the ASE synthesis. Technologies that need to be focused in ASE tests are emphasized, followed by a brief introduction to some representative examples of overseas ASE tests in the recent decade. Some new directions towards advanced ASE research are indicated, and also suggestions are provided for domestic ASE research. ©, 2015, AAAS Press of Chinese Society of Aeronautics and Astronautics. All right reserved.
Chong-Wu H.E.,AVIC The First Aircraft Institute
AIAA Flight Testing Conference 2015, MFT 2015 - Held at the AIAA Aviation Forum 2015 | Year: 2015
This paper presents a method for optimized calculation forces for a full-scale aircraft structure fatigue test that attempts to match aerodynamic and inertia nodal forces rather than shear moment and torque diagrams. Application of method to the full-scale fatigue test of one aircraft structure is described; and details process of method is provided. It is shown that the method can produce an equilibrium for aircraft structure while providing a more realistic load distribution. © 2015, American Institute of Aeronautics and Astronautics Inc. All rights reserved.
Wang X.M.,Northwestern Polytechnical University |
Wang Y.F.,AVIC The First Aircraft Institute |
Lu Z.Z.,Northwestern Polytechnical University |
Deng C.H.,Xian Aerospace Propulsion Institute |
Yue Z.F.,Northwestern Polytechnical University
Mechanics of Materials | Year: 2010
This paper presents the results of a series of experiments to investigate the superelastic cyclic stress-strain responses of NiTi shape memory alloys under tension-torsion biaxial loading conditions. The uniaxial tension and torsion experiments were also conducted to make comparisons. Experiments were controlled by axial displacement and torsional angle in sine wave form with fixed maximum values. Saturation is reached after 30 cycles. The evolutions of equivalent stress-strain curves as well as the separated tensile and shear stress-strain curves during cycling are analyzed. Dissipated energy density, characteristic stresses and strains as functions of deformation cycles are paid attention. Results show that the mechanical responses are significantly affected by the loading path. The stress-strain behaviors under proportional loading are similar to those under uniaxial loading. With the increase of the out-of-phase angle during the non-proportional loading, the special phase transformation exhibition totally disappears in the equivalent stress-strain curves. © 2009 Elsevier Ltd. All rights reserved.
Yang C.,AVIC the First Aircraft Institute |
Zhang J.,Nanjing University of Aeronautics and Astronautics
Chinese Journal of Aeronautics | Year: 2012
A series of computations is conducted for many multi-hole arrangements at several blowing ratios to further investigate the evolution of the film from multi-holes. The influence of multi-hole arrangement on effusion film cooling is analyzed and a preliminary relationship evaluating the film development from developing state to developed state is brought forward. Results show that the coolant jets from front rows of multi-holes merge rapidly and the strength of the kidney vortices due to mainstream-coolant jet interaction in the downstream region are mitigated under super-long-diamond arrangement where the streamwise hole-to-hole pitch is bigger than spanwise hole-to-hole pitch. The holes array arranged in super-long-diamond mode is not only in favor of obtaining developed film layer, but also improving averaged adiabatic film cooling effectiveness. © 2012 Chinese Journal of Aeronautics.
Liang B.,Northwestern Polytechnical University |
Li Y.,Northwestern Polytechnical University |
Li R.,AVIC the first aircraft institute
Journal of Computers | Year: 2011
With the background of the development of Aircraft Anti-skid Braking System, a new aircraft Electro- Hydrostatic Actuator (EHA) of a certain model fighter is designed to meet the need of the braking system. The paper describes the principle of work and features of the EHA, and gives the specific requirements of the system. The selection and performance of the motor, pump and hydraulic cylinder are optimized. Then, the paper describes the principle of work and features of the EHA, models and simulates it with MATLAB/Simulink., and analyzes the effects of all structural parameters on the performance. The results of EHA reach the design target of dynamic performance. Finally, the whole model of the aircraft system is built and established based on the EHA model and results. The results of the dry runway condition verify the correctness of the EHA design, so the Hydro Actuator of traditional aircraft anti-skid braking system could be replaced by EHA. © 2011 ACADEMY PUBLISHER.
Yu J.,AVIC the First Aircraft Institute
Proceedings of 2010 Asia-Pacific International Symposium on Aerospace Technology, APISAT 2010 | Year: 2010
This paper applies the idea of swing arm mechanism trailing edge flap and modeled the mechanism on CATIA software to yield a kinematic simulation for the purpose of check motion trail and force transfer in this mechanism. Relevant works such as actuation, mass and stress analysis are also involved. A spanwise constraint is added to eliminate spanwise displacement of the trailing edge flap while deploying. A four-row ball monorail guidance system is introduced into the outside swing arm assembly to provide spanwise slide motion for the support bracket. As the result of this research project, it is found that swing arm mechanism trends to require relatively small fairings for supports and attachments due to its high stowed space utilizing efficiency. Initial mass estimation carried out in this paper also indicates that the new design takes advantage in terms of weight comparing with traditional trailing edge flap mechanisms. Thus, swing arm mechanism is supposed to show great competitive potential for commercial airliner's trailing edge flaps after further analysis has been done in the detail design phase.
Tang C.,AVIC the First Aircraft Institute |
Wang L.,AVIC the First Aircraft Institute
Procedia Engineering | Year: 2015
A numerical simulation method for the wind field over complex terrain was developed. The complex terrain was represented by a surface, which was established by the surface spline method based on the contour line of the map. Then it was divided into panels containing vortex ring singularities. The singularity distribution was solved by combining with the potential flow theory and the boundary condition of terrain surface. Finally, the wind filed was simulated by linear superposition of uniform stream and induced velocity of vortex rings. An example was studied, and the result was also compared with Weather Research and Forecasting (WRF) method. It indicates that the method proposed could describe the terrain much more accurately and provide a reasonable result of wind field distribution. © 2015 The Authors.
Jiali W.,AVIC the First Aircraft Institute |
Yanna L.,AVIC the First Aircraft Institute
Procedia Engineering | Year: 2015
The primary purpose of temperature control for cooling system is to ensure the system discharge temperature within target range while preventing compressor outlet temperature from overheating. A two-level subsection control method is constructed to control the compressor outlet temperature and the system discharge temperature respectively. In addition, the target value of system discharge temperature is divided into three parts. In every part, the different target value of the compressor outlet temperature is given.The methodnot only makes sure that controlling the system discharge temperature is easier to be accomplished, but also reduces cost-compensation of system. The simulation result indicates that the system discharge temperature can be regulated smoothly to target value while controlling the compressor outlet temperature in design value. Meanwhile,the ram air valve (RAV) and the temperature control valve (TCV) are under normal condition during all processes. © 2015 Published by Elsevier Ltd.
Liu C.,AVIC the First Aircraft Institute |
Wang B.,AVIC the First Aircraft Institute
Nanjing Hangkong Hangtian Daxue Xuebao/Journal of Nanjing University of Aeronautics and Astronautics | Year: 2016
Arrestment process is very essential when the carrier-based aircraft is landing on the deck of an aircraft carriers. Landing response of the carrier-based aircraft is not only dominated by given landing weight of the aircraft and buffering properties of the landing gear system, but also determined by mechanism performance of the arresting gear system. The modeling method for the carrier-based aircraft coupled with the arresting gear system is presented. The detailed numerical dynamics model of the carrier-based aircraft coupled with the MK 7-3 arresting gear is established by using flexible-rigid coupled dynamics method. Validation of the model is demonstrated by numerical example. Interaction between the carrier-based aircraft and the arresting gear system can be described precisely by using the established model. Analytical results match well with the test data. © 2016, Editorial Department of Journal of NUAA. All right reserved.