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 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.

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

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.

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.

Limit Cycle Flutter Analysis of a High-Aspect-Ratio Wing with an External Store

2014 ◽  
Vol 912-914 ◽  
pp. 907-910 ◽  
Author(s):  
Jun Xu ◽  
Xiao Ping Ma
Keyword(s):  
Aspect Ratio ◽  
Limit Cycle ◽  
High Aspect Ratio ◽  
Structural Model ◽  
Bifurcation Diagrams ◽  
Governing Equations ◽  
Time Simulation ◽  
Flutter Analysis ◽  
Structural Nonlinearities ◽  
Limit Cycle Flutter

Limit cycle flutter analysis of a high-aspect-ratiowing with an external store is presented. The concentrated store mass iscombined into the governing equations which are obtained using the extendedHamilton’s principle. The high-aspect-ratio wing structural model, which alsoconsiders the in-plane bending motion, is used. Three possible nonlinearitiesare considered including structural nonlinearities, aerodynamic nonlinearities,and store nonlinearities. Time simulation and bifurcation diagrams areperformed to analysis systems with three nonlinearities.

Sign in / Sign up

Export Citation Format

Share Document