Effects of multiple structural nonlinearities on limit cycle oscillation of missile control fin

• Published in: Journal of fluids and structures Vol. 27; no. 4; pp. 623 - 635
• Main Authors: Seo, Young-Jin, Lee, Seung-Jun, Bae, Jae-Sung, Lee, In
• Format: Journal Article
• Language: English
• Published: Kidlington Elsevier Ltd 01.05.2011; Elsevier
• Subjects: Aerodynamics; Aeroelasticity; Applied fluid mechanics; Approximation; DPM; Exact sciences and technology; Fluid dynamics; Flutter; Freeplay; Frequency domains; Fundamental areas of phenomenology (including applications); LCO; Limit cycle oscillations; Mathematical models; Multiple structural nonlinearities; Nonlinearity; Physics; Solid mechanics; Structural and continuum mechanics; Vibration; Vibration, mechanical wave, dynamic stability (aeroelasticity, vibration control...); DPM; LCO; Multiple structural nonlinearities; Aeroelasticity; Freeplay; Supersonic flow; Wing; Vibration; Aeroelastic flutter; Aerodynamics; Aerodynamic force; Frequency domain method; Iterative method; Fin; Mechanical clearance; Unsteady flow; Modeling; Missile; Time domain method; Stability boundary; Non linear effect; Limit cycle
• ISSN: 0889-9746; 1095-8622
• DOI: 10.1016/j.jfluidstructs.2011.02.009

Aeroelastic analyses are performed for a 2-D typical section model with multiple nonlinearities. The differences between a system with multiple nonlinearities in its pitch and plunge spring and a system with a single nonlinearity in its pitch are thoroughly investigated. The unsteady supersonic aerodynamic forces are calculated by the doublet point method (DPM). The iterative V-g method is used for a multiple-nonlinear aeroelastic analysis in the frequency domain and the freeplay nonlinearity is linearized using a describing function method. In the time domain, the DPM unsteady aerodynamic forces, which are based on a function of the reduced frequency, are approximated by the minimum state approximation method. Consequently, multiple structural nonlinearities in the 2-D typical wing section model are influenced by the pitch to plunge frequency ratio. This result is important in that it demonstrates that the flutter speed is closely connected with the frequency ratio, considering that both pitch and plunge nonlinearities result in a higher flutter speed boundary than a conventional aeroelastic system with only one pitch nonlinearity. Furthermore, the gap size of the freeplay affects the amplitude of the limit cycle oscillation (LCO) to gap size ratio.