Nonlinear body-freedom flutter analysis in aircraft with the flexible wing

Document Type : Research Paper

Authors

1 Faculty of Aerospace Engineering, K N Toosi University of Technology

2 K. N. Toosi University of technology

Abstract

In aircraft with flexible high aspect ratio wings, it is possible to couple flight dynamics modes and aeroelasticity. This coupling can lead to the body-freedom flutter (BFF) phenomenon, which is the subject of this article. In this study, the planar flight dynamics assumption and the model of a complete aircraft with flexible wings have been used. In this type of aircraft, due to the high aspect ratio of the wings, the effects of nonlinear terms on the dynamic response of the aircraft cannot be ignored. Therefore, for modeling the structure, the generalized nonlinear flexible Euler-Bernoulli beam model with bending-bending-torsion degrees of freedom and for modeling the aerodynamics, the Wagner function with the static stall model has been used. Using the developed model, the nonlinear behavior of the wing and the aircraft due to the occurrence of the BFF and wing flutter (WF) is studied. Also, a sensitivity analysis for the BFF is done and post-instability limit cycle oscillations and subcritical behaviors are investigated.

Keywords

Main Subjects


[1] Niblett, LL T. "The fundamentals of body-freedom flutter." The Aeronautical Journal 90, no. 899 (1986): 373-377.
[2] Shi, Pengtao, Jihai Liu, Yingsong Gu, Zhichun Yang, and Pier Marzocca. "Full-Span Flying Wing Wind Tunnel Test: A Body Freedom Flutter Study." Fluids 5, no. 1 (2020): 34.
[3] Richards, Phillip W., Yuan Yao, Robert A. Herd, Dewey H. Hodges, and Pezhman Mardanpour. "E_ect of inertial and constitutive properties on body-freedom flutter for flying wings." Journal of Aircraft 53, no. 3 (2016): 756-767.
[4] Mardanpour, Pezhman, Dewey H. Hodges, Ryan Neuhart, and Nathan Graybeal. "Engine placement e_ect on nonlinear trim and stability of flying wing aircraft." Journal of Aircraft 50, no. 6 (2013): 1716-1725.
[5] Mardanpour, Pezhman, Phillip W. Richards, Omid Nabipour, and Dewey H. Hodges. "E_ect of multiple engine placement on aeroelastic trim and stability of flying wing aircraft." Journal of Fluids and Structures 44 (2014): 67-86.
[6] Love, Michael, P. Zink, Paul Wieselmann, and Harold Youngren. "Body freedom flutter of high aspect ratio flying wings." In 46th AIAA/ASME/ASCE/AHS/ASC Structures, Structural Dynamics and Materials Conference, p. 1947. 2005.
[7] Li, Yuan Dong, Xin Ping Zhang, Ying Song Gu, and Zhi Chun Yang. "Body freedom flutter study and passive flutter suppression for a high aspect ratio flying wing model." In Applied Mechanics and Materials, vol. 608, pp. 708-712. Trans Tech Publications Ltd, 2014.
[8] Huang  Chao, Y. A. N. G. Chao, W. U. Zhigang, and T. A. N. G. Changhong. "Variations of flutter mechanism of a span-morphing wing involving rigid-body motions." Chinese Journal of Aeronautics 31, no.3 (2018): 490-497.
[9] Iannelli, Andrea, Andr_es Marcos, and Mark Lowenberg. "Study of flexible aircraft body freedom flutter with robustness tools." Journal of Guidance, Control, and Dynamics 41.5 (2018): 1083-1094.
[10] Nejati, Mahdi, Saeed Shokrollahi, Sh Shams, and Ramin Torkaman. "A modi_ed indicial functions approximation for nonlinear aeroelastic analysis." Scientia Iranica 27, no. 3 (2020): 1230-1254.
[11] M. J. Patil, D. H. Hodges, C. E. S. Cesnik, Limit-Cycle Oscillations in High Aspect Ratio Wings, J. Fluids and Structures, Vol. 15 (2001), 107-132.
[12] Kim, Kiun. Nonlinear aeroelastic analysis of aircraft wing-with-store configurations. Texas AM University, 2004.
[13] Badiei, D., M. H. Sadr, and Sh Shams. "Static stall model in aeroelastic analysis of a exible wing with geometrical nonlinearity." Journal of Aerospace Engineering 27.2 (2014): 378-389.
[14] Schmidt, David. Modern ight dynamics. McGraw-Hill Higher Education, 2011.
[15] Crespo da Silva, M. R. M., and C. C. Glynn. "Nonlinear exural-exuraltorsional dynamics of inextensional beams. I. Equations of motion." Journal of Structural Mechanics 6, no. 4 (1978): 437-448.
[16] Crespo da Silva, M. R. M., and C. C. Glynn. "Nonlinear exural-exuraltorsional dynamics of inextensional beams. II. Forced motions." Journal of Structural Mechanics 6, no. 4 (1978): 449-461.
[17] Shams, Sh, MH Sadr Lahidjani, and H. Haddadpour. "Nonlinear aeroelastic response of slender wings based on Wagner function.