Eventos Anais de eventos
COBEM 2017
24th ABCM International Congress of Mechanical Engineering
Aeroelastic Modeling of Low Speed Pitching Oscillations Induced by Stall Considering Nonlinear Springs
Submission Author:
Carlos Renan dos Santos , Noruega , Brazil
Co-Authors:
Carlos Renan dos Santos, Flavio D. Marques
Presenter: Carlos Renan dos Santos
doi://10.26678/ABCM.COBEM2017.COB17-0045
Abstract
Beyond the flutter velocity, a nonlinear aeroelastic system can oscillate in a limit cycle condition. With vibrations reaching higher angles of attack, nonlinear aerodynamic effects like dynamic stall become relevant and dominant. The modeling of structural and aerodynamic effects during stall-induced oscillations is crucial for understanding the phenomenon. In this sense, the present work proposes an investigation on the influence of structural nonlinearities on the aeroelastic behavior of a pitching airfoil. A computational model which couples the equation of motion for a typical section with the Beddoes-Leishman model for unsteady aerodynamics is employed. The model is validated and the behavior of the system is analyzed by considering a pitch spring with stiffness represented by hardening, softening, and freeplay nonlinear effects. It was concluded that structural stiffness can affect the flutter onset velocity and the behavior of the stall-induced oscillations as the airspeed varies.
Keywords
nonlinear aeroelasticity, Stall Flutter, Beddoes-Leishman model, Stall-induced oscillations (SIO), dynamic stall
