Low speed flutter and limit cycle oscillations of a two-degree-of-freedom flat plate in a wind tunnel

Xavier Amandolese (1, 2) , Sébastien Michelin (1) , M. Choquel (1)

1 LadHyX - Laboratoire d'hydrodynamique
2 Département ISME

This paper explores the dynamical response of a two-degree-of-freedom flat plate undergoing classical coupled-mode flutter in a wind tunnel. Tests are performed at low Reynolds number (Re similar to 2.5 x 10(4)), using an aeroelastic set-up that enables high amplitude pitch-plunge motion. Starting from rest and increasing the flow velocity, an unstable behaviour is first observed at the merging of frequencies: after a transient growth period the system enters a low amplitude limit-cycle oscillation regime with slowly varying amplitude. For higher velocity the system transitions to higher-amplitude and stable limit cycle oscillations (LCO) with amplitude increasing with the flow velocity. Decreasing the velocity from this upper LCO branch the system remains in stable self-sustained oscillations down to 85% of the critical velocity. Starting from rest, the system can also move toward a stable LCO regime if a significant perturbation is imposed. Those results show that both the flutter boundary and post-critical behaviour are affected by nonlinear mechanisms. They also suggest that nonlinear aerodynamic effects play a significant role. (C) 2013 Elsevier Ltd. All rights reserved.

Domaines: Mécanique des fluides [physics.class-ph]; Mécanique des fluides [physics.class-ph]

Xavier Amandolese, Sébastien Michelin, M. Choquel. Low speed flutter and limit cycle oscillations of a two-degree-of-freedom flat plate in a wind tunnel. Journal of Fluids and Structures, 2013, 43, pp.244-255. ⟨10.1016/j.jfluidstructs.2013.09.002⟩. ⟨hal-00996423⟩