Influence of Nonlinear Static Deformation on the Pre-Pazy and Pazy Wing Flutter

Author(s)

Santos, Joao P. T. P. ; Marques, Flavio D. ; Begnini, Guilherme R.

• Document type: Journal article
• Source: JOURNAL OF AIRCRAFT; v. 62, n. 1, p. 20-pg., 2024-12-20.

Abstract

This paper investigates the influence of a nonlinear static deformation on the dynamic aeroelastic behavior of very flexible wings. The objects of study are the Pre-Pazy and Pazy wings, which are highly flexible wings presented by the Large Deflections Working Group of the Third Aeroelastic Prediction Workshop. A nonlinear static aeroelastic coupling analysis is performed, coupling a nonlinear beam formulation with the Vortex Lattice Method. The natural frequencies and mode shapes of the wing are obtained considering the predeformed structure, and these results serve as input data for the dynamic aeroelastic model, which considers the Unsteady Vortex Lattice Method as the aerodynamic model and serves to yield the aeroelastic responses in modal coordinates. The frequency spectrum of each time response serves as input for a system identification method, which considers the Least Squares Complex Frequency-domain estimator. The velocity-damping-frequency diagrams are obtained from the identified frequencies and damping ratios, and the critical flutter condition is determined. The flutter speeds obtained agree with the references, and the differences are up to 77% for the Pre-Pazy wing and 4% for the Pazy wing. A significant reduction in those speeds is observed with an increase in the angle of attack. (AU)

• FAPESP's process: 23/15547-7 - Aeroelastic analysis of highly flexible wings considering the coupling with rotating proppelers
• Grantee: João Pedro Tavares Pereira dos Santos
• Support Opportunities: Scholarships in Brazil - Doctorate