scholarly journals Bifurcations of limit-cycle oscillations of a two degree-of-freedom airfoil caused by aerodynamic non-linearities

2017 ◽  
Author(s):  
Anna C. van Rooij ◽  
Jens Nitzsche ◽  
Richard P. Dwight
Keyword(s):  
Limit Cycle ◽  
Degree Of Freedom ◽  
Limit Cycle Oscillations ◽  
Two Degree Of Freedom

Triggering Mechanisms of Limit Cycle Oscillations in a Two Degree-of-Freedom Wing Flutter Model

2005 ◽  
Author(s):  
Young S. Lee ◽  
Alexander F. Vakakis ◽  
Lawrence A. Bergman ◽  
D. Michael McFarland ◽  
Gae¨tan Kerschen
Keyword(s):  
Limit Cycle ◽  
Degree Of Freedom ◽  
Resonance Capture ◽  
Limit Cycle Oscillations ◽  
Wing Flutter ◽  
Wing Model ◽  
Pitch Frequency ◽  
Frequency Components ◽  
Triggering Mechanisms ◽  
Two Degree Of Freedom

We show numerically that the triggering mechanisms of limit cycle oscillations (LCOs) due to aeroelastic instability are composed of a series of resonance captures. We consider a two degree-of-freedom (DOF) wing model with cubic nonlinear stiffnesses in the support, assuming quasi-steady aerodynamics and subsonic flow around the wing. Then, we establish the slow flow dynamics model, using the complexification / averaging technique and considering three frequency components; i.e., the two linear natural frequencies corresponding to heave and pitch and the superharmonic component which appears as three times the pitch frequency. It turns out that the LCO triggering mechanisms consist of mainly three stages: (i) transient resonance capture (TRC); (ii) escape; and (iii) permanent resonance capture (PRC). We examine the characteristics of each stage by way of time response, wavelet transform, phase plane, and instantaneous energy.

Sign in / Sign up

Export Citation Format

Share Document