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

M. Candon, R. Carrese, H. Ogawa, P. Marzocca

Research output: Contribution to journalArticlepeer-review

5 Citations (Scopus)


Higher-Order Spectra (HOS) are used to characterise the nonlinear aeroelastic behaviour of a plunging and pitching 2-degree-of-freedom aerofoil system by diagnosing structural and/or aerodynamic nonlinearities via the nonlinear spectral content of the computed displacement signals. The nonlinear aeroelastic predictions are obtained from high-fidelity viscous fluid-structure interaction simulations. The power spectral, bi-spectral and tri-spectral densities are used to provide insight into the functional form of both freeplay and inviscid/viscous aerodynamic nonlinearities with the system displaying both low- and high-amplitude Limit Cycle Oscillation (LCO). It is shown that in the absence of aerodynamic nonlinearity (low-amplitude LCO) the system is characterised by cubic phase coupling only. Furthermore, when the amplitude of the oscillations becomes large, aerodynamic nonlinearities become prevalent and are characterised by quadratic phase coupling. Physical insights into the nonlinearities are provided in the form of phase-plane diagrams, pressure coefficient distributions and Mach number flowfield contours.

Original languageEnglish
Pages (from-to)1530-1560
Number of pages31
JournalAeronautical Journal
Issue number1244
Publication statusPublished - Oct 1 2017
Externally publishedYes

All Science Journal Classification (ASJC) codes

  • Aerospace Engineering


Dive into the research topics of 'Identification of freeplay and aerodynamic nonlinearities in a 2D aerofoil system with via higher-order spectra'. Together they form a unique fingerprint.

Cite this