Higher-Order Spectral Analysis of a Nonlinear Pitch and Plunge Apparatus

Abstract

Simulated aeroelastic responses of a nonlinear pitch and plunge apparatus are analyzed using various statistical signal processing techniques including higher-order spectral methods. A MATLAB version of the Nonlinear Aeroelastic Testbed Apparatus (NATA) at the Texas A&M University is used to generate various aeroelastic response data including limit cycle oscillations (LCO). Traditional and higher-order spectral (HOS) methods are applied to the simulated aeroelastic responses. Higher-order spectral methods are used to identify critical signatures that indicate the transition from linear to nonlinear (LCO) aeroelastic behavior.

Identification of freeplay and aerodynamic nonlinearities in a 2D aerofoil system with via higher-order spectra

“…HOS methods have been utilised to analyse various nonlinear aeroelastic studies including the analysis of wind-tunnel and flight test experiments, and fundamental research (19) . Experimental flutter wind-tunnel results of a pitch/plunge apparatus were analysed using HOS in a study conducted by Silva et al (20) . The analysis proved beneficial in identifying regions of linear and nonlinear behaviour and also in identifying the transition from linear to nonlinear aeroelastic behaviour.…”

Internal Resonance and Stall Flutter Interactions in a Pitch-Flap Wing in the Wind-Tunnel

“…The Pitch And Plunge Apparatus (PAPA) was used to test flutter control mechanisms at transsonic airspeeds by Mukhopadhvay V. [6]. Several structurally nonlinear setups were built such as the Nonlinear Aeroelastic Testbed Apparatus (NATA) (O'Neil et al [7] and Silva et al [8]) which uses a cam system to get different continuous nonlinearities on the pitch and plunge DOFs. The NATA was also used by Dowell et al [9] for teaching purposes.…”