Effects of geometric structural nonlinearity on flutter and limit cycle oscillations of high-aspect-ratio wings

2004 ◽  
Vol 19 (3) ◽  
pp. 291-306 ◽  
Author(s):  
D.M. Tang ◽  
E.H. Dowell
Keyword(s):  
Aspect Ratio ◽  
Limit Cycle ◽  
High Aspect Ratio ◽  
Limit Cycle Oscillations ◽  
Structural Nonlinearity

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

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

Flutter/LCO suppression for high-aspect ratio wings

2009 ◽  
Vol 113 (1144) ◽  
pp. 409-416 ◽  
Author(s):  
D. Tang ◽  
E. H. Dowell
Keyword(s):  
Aspect Ratio ◽  
Limit Cycle ◽  
High Aspect Ratio ◽  
Equations Of Motion ◽  
Wind Tunnel Test ◽  
Beam Theory ◽  
Control Device ◽  
Structural Equations ◽  
Limit Cycle Oscillations ◽  
Tip Mass

Abstract An experimental high-aspect ratio wing aeroelastic model with a device to provide a controllable slender body tip mass distribution has been constructed and the model response due to flutter and limit cycle oscillations has been measured in a wind tunnel test. A theoretical model has also been developed and calculations made to correlate with the experimental data. Structural equations of motion based on nonlinear beam theory are combined with the ONERA aerodynamic stall model (an empirical extension of Theodorsen aerodynamic theory that accounts for flow separation). A dynamic perturbation analysis about a nonlinear static equilibrium is used to determine the small perturbation flutter boundary which is compared to the experimentally determined flutter velocity and flutter frequency. Time simulation is used to compute the limit cycle oscillations response when the flutter/LCO control system is ON or OFF. Theory and experiment are in good agreement for predicting the flutter/LCO suppression that can be achieved with the control device.

scholarly journals Numerical Continuation of Limit Cycle Oscillations and Bifurcations in High-Aspect-Ratio Wings

Aerospace ◽  
2018 ◽  
Vol 5 (3) ◽  
pp. 78 ◽  
Author(s):  
Andrew Eaton ◽  
Chris Howcroft ◽  
Etienne Coetzee ◽  
Simon Neild ◽  
Mark Lowenberg ◽  
...  
Keyword(s):  
Aspect Ratio ◽  
Limit Cycle ◽  
High Aspect Ratio ◽  
Geometric Nonlinearity ◽  
Numerical Continuation ◽  
Torsional Stiffness ◽  
Beam Model ◽  
Limit Cycle Oscillations ◽  
Strip Theory ◽  
Parameter Continuation

This paper applies numerical continuation techniques to a nonlinear aeroelastic model of a highly flexible, high-aspect-ratio wing. Using continuation, it is shown that subcritical limit cycle oscillations, which are highly undesirable phenomena previously observed in numerical and experimental studies, can exist due to geometric nonlinearity alone, without need for nonlinear or even unsteady aerodynamics. A fully nonlinear, reduced-order beam model is combined with strip theory and one-parameter continuation is used to directly obtain equilibria and periodic solutions for varying airspeeds. The two-parameter continuation of specific bifurcations (i.e., Hopf points and periodic folds) reveals the sensitivity of these complex dynamics to variations in out-of-plane, in-plane and torsional stiffness and a ‘wash out’ stiffness coupling parameter. Overall, this paper demonstrates the applicability of continuation to nonlinear aeroelastic analysis and shows that complex dynamical phenomena, which cannot be obtained by linear methods or numerical integration, readily exist in this type of system due to geometric nonlinearity.

The Effect of Structural Geometric Nonlinearities on the Flutter of the Straight and Swept Wing Configurations

2012 ◽  
Vol 189 ◽  
pp. 306-311 ◽  
Author(s):  
Qing Guo ◽  
Bi Feng Song
Keyword(s):  
Aspect Ratio ◽  
High Aspect Ratio ◽  
Swept Wing ◽  
Geometric Nonlinearities ◽  
Air Vehicle ◽  
Structural Nonlinearity ◽  
Flutter Analysis ◽  
Long Endurance ◽  
The Impact ◽  
Straight Wing

High altitude and long endurance (HALE) vehicle always adopt straight or swept configuration, which leads to the problem that the wings of UAV have high aspect ratio and are very flexible. This kind of flexible wing exhibits large deformation when aerodynamic forces are loaded on them and the structural nonlinearity should be considered. So the dynamic and flutter characteristics will be changed. In the engineering applications, the effects of structural geometric nonlinearities on the air vehicle design are the most concerns of aeroelasticity before a systematic flutter analysis for the air vehicle. because the solution for nonlinear flutter speed based on the CFD-CSD method is complex and time consuming. In this paper, we propose a simple and efficient approach that can analyze the effect of structural geometric nonlinearities on the flutter characteristics of high aspect ratio wing quickly. And a straight wing and a straight-swept wing are analyzed to verify the feasibility and efficiency of the proposed method. It is found that the effect of structural geometric nonlinearities has a strong effect on the flutter characteristic of the straight wing, but is weak on the straight-swept wing. And finally the impact of swept angle on the dynamic and flutter characteristics of straight-swept wing is also discussed.

FLUID-STRUCTURE INTERACTION ANALYSIS OF A HIGH-ASPECT-RATIO WING CONSIDERING STRUCTURAL NONLINEARITY

2009 ◽  
Vol 23 (03) ◽  
pp. 445-448
Author(s):  
KYUNG-SEOK KIM ◽  
IN-GYU LIM ◽  
IN LEE ◽  
JAE-HAN YOO
Keyword(s):  
Aspect Ratio ◽  
High Aspect Ratio ◽  
Large Deflection ◽  
Interaction Analysis ◽  
Fluid Structure Interaction ◽  
Inverse Transformation ◽  
Fluid Structure ◽  
Structure Interaction ◽  
Structural Nonlinearity ◽  
Interaction Problem

In this research, fluid-structure interaction problem including geometric structural nonlinearity is studied for a high-aspect-ratio wing. When a high-aspect-ratio wing structure is interacted with external airload, geometric structural nonlinearity can be caused by large deflection of a wing. For the investigation of such a fluid-structure interaction problem, the transonic small disturbance theory for the aerodynamic analysis and the large deflection beam theory for the structural analysis are used, respectively. For the coupling between fluid and structure, the transformation of a displacement from the structural mesh to the aerodynamic grid is performed by a shape function which is used for the finite element and the inverse transformation of force by work equivalent load method. Static deformations in the vertical and twist deflections caused by gravity loading are compared with experimental results. Also, static aeroelastic analysis results are compared with experimental data. From the analysis results, effects of structural nonlinearity on static aeroelastic characteristics are investigated.

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.

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