TY - GEN
T1 - Investigation of the role of higher order torsion & bending modes in flutter stability for flexible slender wings
AU - Bottai, Auriane M.A.
AU - Jonson, Michael L.
AU - Campbell, Robert L.
N1 - Funding Information:
In recent years, environmental concerns and economic constraints have urged aircraft designers to improve drastically aircraft fuel efficiency. In this context, the Advanced Aerodynamic Design Center for Ultra-Efficient Commercial Vehicles was funded by NASA at the University of Tennessee, Knoxville [1,2] to develop a light-weight, and aerodynamically improved wing design for a medium-size commercial aircraft. The objective of the design is to reach a 70% increase in aircraft fuel efficiency. One of the main features of this concept vehicle is a high-aspect ratio truss-braced wing. Such structures present the advantage of reducing the lift-induced contribution to drag, which can represent up to 43% of the overall aerodynamic drag of a large transport aircraft in cruise (Abbas et al. [3]).
Funding Information:
This work was supported by the National Aeronautics and Space Administration (NASA), under the University Leadership Initiative (ULI) at The Pennsylvania State University as a subcontract to the University of Tennessee Knoxville for the "Advanced Aerodynamic Design Center for Ultra-Efficient Commercial Vehicles" (Award NNX17AJ95A).
Publisher Copyright:
© 2019, American Institute of Aeronautics and Astronautics Inc, AIAA. All rights reserved.
PY - 2019
Y1 - 2019
N2 - A Galerkin method is used to study flutter stability of a high aspect ratio wing. Polynomial approximations of the wing mode shapes are obtained with an improved Rayleigh-Ritz method: essential and boundary conditions are taken into account by the means of Lagrange Multipliers, which improves accuracy in the natural frequencies and the mode shapes. Those polynomial functions are then used to analyze the flutter stability of the torsion, vertical bending and fore-aft bending of several variations of a tapered wing design in an eigenvalue approach. The first torsion mode was found to couple with the third out-of-plane bending mode of the swept back tapered wing, with reduced torsional rigidity. Past the coalescence point, the modes combine either torsion and high order out-of plane bending, or out-of plane and low order in-plane bending. The later plays no role in flutter stability; however it couples with the other degree of freedom at higher speed and hence may affect the response of the wing to any external disturbance.
AB - A Galerkin method is used to study flutter stability of a high aspect ratio wing. Polynomial approximations of the wing mode shapes are obtained with an improved Rayleigh-Ritz method: essential and boundary conditions are taken into account by the means of Lagrange Multipliers, which improves accuracy in the natural frequencies and the mode shapes. Those polynomial functions are then used to analyze the flutter stability of the torsion, vertical bending and fore-aft bending of several variations of a tapered wing design in an eigenvalue approach. The first torsion mode was found to couple with the third out-of-plane bending mode of the swept back tapered wing, with reduced torsional rigidity. Past the coalescence point, the modes combine either torsion and high order out-of plane bending, or out-of plane and low order in-plane bending. The later plays no role in flutter stability; however it couples with the other degree of freedom at higher speed and hence may affect the response of the wing to any external disturbance.
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U2 - 10.2514/6.2019-3389
DO - 10.2514/6.2019-3389
M3 - Conference contribution
AN - SCOPUS:85099460047
SN - 9781624105890
T3 - AIAA Aviation 2019 Forum
SP - 1
EP - 19
BT - AIAA Aviation 2019 Forum
PB - American Institute of Aeronautics and Astronautics Inc, AIAA
T2 - AIAA Aviation 2019 Forum
Y2 - 17 June 2019 through 21 June 2019
ER -