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Aeroelastic modelling and stability analysis of tiltrotor aircraft in conversion flight

Published online by Cambridge University Press:  12 September 2018

Z. Li Open the ORCID record for Z. Li [Opens in a new window]  and
P. Xia Open the ORCID record for P. Xia [Opens in a new window]
Z. Li
Affiliation:
National Key Laboratory of Rotorcraft AeromechanicsCollege of Aerospace EngineeringNanjing University of Aeronautics and AstronauticsNanjing, China
P. Xia*
Affiliation:
National Key Laboratory of Rotorcraft AeromechanicsCollege of Aerospace EngineeringNanjing University of Aeronautics and AstronauticsNanjing, China
*
xiapq@nuaa.edu.cn
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Abstract

In conversion flight, the aeroelastic modelling of tiltrotor aircraft needs to consider the unsteady effect of the rotor wake bending due to the rotor tilting. In this paper, the unsteady models of the rotor wake bending and dynamic inflow have been introduced into the aeroelastic modelling of the tiltrotor aircraft in conversion flight by using Hamilton’s generalized principle. The method for solving the aeroelastic stability of tiltrotor aircraft in conversion flight has been established by using the small perturbation theory and the Floquet theory. The influences of unsteady dynamic inflow on trim control inputs and aeroelastic stability of a tiltrotor aircraft in conversion flight were calculated and analysed. The calculation results show that the required collective pitch increases with the pylon tilting forward and the unsteady inflow is trimmed primarily by the lateral cyclic pitch of the rotor. The wake bending unsteady dynamic inflow can obviously reduce the stability of the flapping modes of the rotor, and have no obvious influence on the lag modes of the rotor and the motion modes of the wing. The instability of tiltrotor occurs in the chordwise bending mode of the wing when the pylon tilts to a certain angle in high speed forward flight.

Keywords

Tiltrotor aircraftconversion flightaeroelastic stabilityrotor wake bendingdynamic inflowunsteady aerodynamic forces
Type
Research Article
Information
The Aeronautical Journal , Volume 122 , Issue 1256 , October 2018 , pp. 1606 - 1629
Copyright
© Royal Aeronautical Society 2018 

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References

1. Kim, T. Advanced analysis on tiltrotor aircraft flutter stability, including unsteady aerodynamics, AIAA J, 2015, 46,(4), pp 1002-1012.Google Scholar
2. Kaza, K. Effects of steady coning angle and damping on whirl flutter stability, J Aircr, 2015, 10, (11), pp 664-6693 Google Scholar
3. Singh, R., Gandhi, F. and Paik, J. Active tiltrotor whirl-flutter stability augmentation using wing-flaperon and swash-plate actuation, J Aircr, 2015, 44, (5) pp 1439-1446.Google Scholar
4. Zhang, J. and Smith, E.C. Influence of aeroelasticity tailored wing extensions and winglets on whirl flutter stability, 2nd Asian Rotorcraft Forum, Tianjin, China, 2013, pp 188-200.Google Scholar
5. Nixon, M.W. Aeroelastic Response and Stability of Tiltrotors with Elastically-coupled Composite Rotor Blades, Ph.D. thesis, University of Maryland, 1994.Google Scholar
6. Slaby, J. and Smith, E. Aeroelastic stability of folding tiltrotor aircraft in cruise flight with composite wings, 52nd AIAA/ASME/ASCE/AHS/ASC Structures, Structural Dynamics and Materials Conference, Denver, Colorado, 2011, pp 2171-2179.Google Scholar
7. Kim, T., Lim, J. and Shin, S.J. Structural design optimization of a tiltrotor aircraft composite wing to enhance whirl flutter stability, Composite Structures, 2013, 95, (1), pp 283-194.Google Scholar
8. He, C.J. Development and Application of Generalized Dynamic Wake Theory for Lifting Rotors, PhD Thesis, Georgia Institute of Technology, 1989.Google Scholar
9. Venkatesan, C. Effects of blade configuration parameters on helicopter rotor structural dynamics and whirl tower loads, Aeronautics J, 2016, 120, (1224), pp 271-290.Google Scholar
10. Kumar, M. and Venkatesan, C. Effects of blade-tip geometry on helicopter trim and control response Aeronautics J – New Series, 2017, pp 1-23.Google Scholar
11. Krothapallik, R., Prasad, J.V. and Peters, D.A. Helicopter rotor dynamic inflow modeling for maneuvering, J of the American Helicopter Soc, 2001, 46, (2), pp 129-139.Google Scholar
12. Yue, H.L. and Xia, P.Q. A wake bending unsteady dynamic inflow model of tiltrotor in conversion flight of tiltrotor aircraft, Science in China Series E-Technological Sciences, 2009, 52, (11) pp 3188-3197.Google Scholar
13. Li, Z.Q. and Xia, P.Q. Whirl Flutter and Rotor Hub Center’s Motion Image of Tiltrotor Aircraft, the 7th Asia Pacific International Symposium on Aerospace Technology, Cairns, Australia, 2015.Google Scholar
14. Bertin, J. and Smith, ML. Incompressible Flow About Wings of Finite Span, Aerodynamics for Engineers. 3rd ed. Prentice-Hall, Upper Saddle River, NJ, 1998, pp 261-336.Google Scholar
15. Saffman, P.G. Vortex Force and Bound Vorticity, Vortex Dynamics, Cambridge University Press, New York, USA, 1992, pp 46-48.Google Scholar
16. Johnson, W. Helicopter Theory, Dover Publication, US, 1994, pp 196-198.Google Scholar
17. Johnson, W. Dynamics of Tilting Proprotor Aircraft in Cruise Flight, Technical Report, NASA/TN D-7677, 1974.Google Scholar
18. Keller, J.D. An investigation of helicopter dynamic coupling using an analytical model, J of American Helicopter Soc, 1996, 41, (4), pp 322-330.Google Scholar
19. Peters, D.A., Kim, B.S. and Chen, H.S. Calculation of trim settings for a helicopter rotor by an optimized controller, J Guidance, Control and Dynamics, 1984, 7, (1), pp 85-97.Google Scholar
20. Wernicke, G. Performance and Safety Aspects of the XV-15 Tilt Rotor Research Aircraft, 33rd AHS Annual National Form, Washington, DC, USA, 1977.Google Scholar