Galloping instability and control of a rigid pendulum in a flowing soap film

Alessandro Orchini (1) , Hamid Kellay (2) , Andrea Mazzino (3, 4)

1 Physics Department, Genova
2 LOMA - Laboratoire Ondes et Matière d'Aquitaine
3 DICCA - Dipartimento di Ingegneria Civile, Chimica e Ambientale [Genova]
4 INFN and CINFAI Consortium, Genova Section

A pendulum suspended in a fast flowing soap film may show sustained oscillations. The conditions necessary for self excited motion to occur are outlined: a flow velocity above a threshold value along with geometrical constraints. The role of vortex shedding is discussed, and the observed instability is shown to be well described by the galloping instability. Experimental results are supported by numerical simulations. Furthermore, we observe that the instability may be suppressed by attaching a long enough filament to the rear of the pendulum.

Mots clés: Fluid-structure interaction; Galloping; Flow Control

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

Alessandro Orchini, Hamid Kellay, Andrea Mazzino. Galloping instability and control of a rigid pendulum in a flowing soap film. Journal of Fluids and Structures, 2015, 56, pp.124-133. ⟨10.1016/j.jfluidstructs.2015.04.006⟩. ⟨hal-01186764⟩