Limit-Cycle Hysteresis Response for a High-Aspect-Ratio Wing Model

2002 ◽  
Vol 39 (5) ◽  
pp. 885-888 ◽  
Author(s):  
Deman Tang ◽  
Earl H. Dowell
Keyword(s):  
Aspect Ratio ◽  
Limit Cycle ◽  
High Aspect Ratio ◽  
Wing Model ◽  
Hysteresis Response

Effects of Aeroelastic Nonlinearity on Flutter and Limit Cycle Oscillations of High-Aspect-Ratio Wings

2011 ◽  
Vol 110-116 ◽  
pp. 4297-4306 ◽  
Author(s):  
Keivan Eskandary ◽  
Morteza Dardel ◽  
Mohammad Hadi Pashaei ◽  
Abdol Majid Kani
Keyword(s):  
Aspect Ratio ◽  
Limit Cycle ◽  
High Aspect Ratio ◽  
Large Deflection ◽  
Limit Cycle Oscillation ◽  
Low Velocity ◽  
Wing Model ◽  
Structural Nonlinearities ◽  
Cycle Oscillation ◽  
Compressibility Effects

In this study aeroelastic characteristics of long high aspect ratio wing models with structural nonlinearities in quasi-steady aerodynamics flows are investigated. The studied wing model is a cantilever wing with double bending and torsional vibrations and with large deflection ability in according to Dowell-Hodges wing model. This wing model is valid for long, straight and thin homogeneous isotropic beams. Aerodynamics model is based on quasi-steady aerodynamic which is valid for aerodynamic flows in low velocity and without wake, viscosity and compressibility effects. The effect of different parameters such as mass ratios and stiffness ratios on flutter and divergence velocities and limit cycle oscillation amplitudes are carefully studied.

Non-linear aeroelastic analysis in the time domain of high-aspect-ratio wings: Effect of chord and taper-ratio variation

2016 ◽  
Vol 121 (1235) ◽  
pp. 21-53 ◽  
Author(s):  
A. Suleman ◽  
F. Afonso ◽  
J. Vale ◽  
É. Oliveira ◽  
F. Lau
Keyword(s):  
Aspect Ratio ◽  
High Aspect Ratio ◽  
Bending Moment ◽  
Equilibrium Solutions ◽  
Computational Framework ◽  
Wing Model ◽  
Aeroelastic Analysis ◽  
Non Linear ◽  
Time Marching ◽  
The Time Domain

ABSTRACTCommercial jets usually have relatively low-aspect-ratio wings, in spite of the associated benefits of increasing the wing aspect-ratio, such as higher lift-to-drag ratios and ranges. This is partially explained by the fact that the wing becomes more flexible by increasing the aspect-ratio that results in higher deflections which can cause aeroelastic instability problems such as flutter. An aeroelastic computational framework capable of evaluating the effects of geometric non-linearities on the aeroelastic performance of high-aspect-ratio wings has been developed and validated using numerical and experimental data. In this work, the aeroelastic performance of a base wing model with 20 m span and 1 m chord is analysed and the effect of changing the wing chord or the taper-ratio is determined. The non-linear static aeroelastic equilibrium solutions are compared in terms of drag polar, root bending moment and natural frequencies, and the change in the flutter speed boundary is assessed as a function of aspect-ratio using a time-marching approach.

The effect of stiffness and geometric parameters on the nonlinear aeroelastic performance of high aspect ratio wings

2016 ◽  
Vol 231 (10) ◽  
pp. 1824-1850 ◽  
Author(s):  
F Afonso ◽  
G Leal ◽  
J Vale ◽  
É Oliveira ◽  
F Lau ◽  
...  
Keyword(s):  
Aspect Ratio ◽  
High Aspect Ratio ◽  
Nonlinear Behavior ◽  
Geometric Parameters ◽  
Torsional Stiffness ◽  
Design Parameters ◽  
Sweep Angle ◽  
Flutter Speed ◽  
Wing Model ◽  
Aspect Ratios

The increase in wing aspect ratio is gaining interest among aircraft designers in conventional and joined-wing configurations due to the higher lift-to-drag ratios and longer ranges. However, current transport aircraft have relatively small aspect ratios due their increased structural stiffness. The more flexible the wing is more prone to higher deflections under the same operating condition, which may result in a geometrical nonlinear behavior. This nonlinear effect can lead to the occurrence of aeroelastic instabilities such as flutter sooner than in an equivalent stiffer wing. In this work, the effect of important stiffness (inertia ratio and torsional stiffness) and geometric (sweep and dihedral angles) design parameters on aeroelastic performance of a rectangular high aspect ratio wing model is assessed. The torsional stiffness was observed to present a higher influence on the flutter speed than the inertia ratio. Here, the decrease of the inertia ratio and the increase of the torsional stiffness results in higher flutter and divergence speeds. With respect to the geometric parameters, it was observed that neither the sweep angle nor the dihedral angle variations caused a substantial influence on the flutter speed, which is mainly supported by the resulting smaller variations in torsion and bending stiffness due to the geometric changes.

LIMIT-CYCLE OSCILLATIONS IN HIGH-ASPECT-RATIO WINGS

2001 ◽  
Vol 15 (1) ◽  
pp. 107-132 ◽  
Author(s):  
M.J. PATIL ◽  
D.H. HODGES ◽  
C.E.S. CESNIK
Keyword(s):  
Aspect Ratio ◽  
Limit Cycle ◽  
High Aspect Ratio ◽  
Limit Cycle Oscillations

Body Freedom Flutter Study and Passive Flutter Suppression for a High Aspect Ratio Flying Wing Model

2014 ◽  
Vol 608-609 ◽  
pp. 708-712 ◽  
Author(s):  
Yuan Dong Li ◽  
Xin Ping Zhang ◽  
Ying Song Gu ◽  
Zhi Chun Yang
Keyword(s):  
Aspect Ratio ◽  
Mass Balance ◽  
High Aspect Ratio ◽  
Center Of Gravity ◽  
The Body ◽  
Design Parameters ◽  
Wing Model ◽  
Design Variables ◽  
Optimization Study ◽  
Tip Mass

Normal mode and flutter analysis are conducted for a high aspect ratio aft swept flying wing model, and body freedom flutter is found to be the most critical aeroelastic instability for this air vehicle model. To determine the influence of various kinds of design parameters on BFF characteristics, eight factors are considered in the parametric study, i.e. wing vertical bending stiffness, weight and center of gravity of the wing root payload and the wing tip mass balance, wing half span, aft swept angle and the station of wing body blended line. After the parametric analysis, the mass and center of gravity of the wing root payload are selected as design variables, and the baseline model is utilized in the design optimization study subject to critical flutter speed constraint. Finally, the optimal mass balance design is suggested to suppress the body freedom flutter phenomenon passively and maximize the payload.

Limit-Cycle Oscillation of High-Aspect-Ratio Wings

2014 ◽  
Vol 556-562 ◽  
pp. 4329-4332
Author(s):  
Yan Ping Xiao ◽  
Yi Ren Yang ◽  
Peng Li
Keyword(s):  
Aspect Ratio ◽  
Limit Cycle ◽  
High Aspect Ratio ◽  
Equations Of Motion ◽  
Beam Theory ◽  
Structural Equations ◽  
Limit Cycle Oscillation ◽  
Nonlinear Beam ◽  
Structural Nonlinearity ◽  
Cycle Oscillation

In this paper structural equations of motion based on nonlinear beam theory and the unsteady aerodynamic forces are gained to study the effects of geometric nonlinearity on the aerodynamic response of high-aspect-ratio wings. Then the Galerkin’s method is used to discretize the equations of motion. The results of HALE wing show good agreement with references. And other results investigate the effects of geometric structural nonlinearity on the response of a wing. Also the complex changes of the limit-cycle oscillation with speed increasing is carefully studied.

Limit cycle oscillations in high-aspect-ratio wings

1999 ◽  
Author(s):  
Mayuresh Patil ◽  
Dewey Hodges ◽  
Carlos Cesnik
Keyword(s):  
Aspect Ratio ◽  
Limit Cycle ◽  
High Aspect Ratio ◽  
Limit Cycle Oscillations
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