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Accueil > Evénements Scientifiques > Conférences et Séminaires > Conférences et séminaires 2012 > Séminaire de Yahya Modarres

Séminaire de Yahya Modarres

5 juin 2012

Dynamics of a slender flexible cylinder placed in flow

Yahya Modarres

Fluid-Structure Interactions Laboratory, Department of Mechanical and Industrial Engineering, University of Massachusetts, Amherst, MA 01003

Mercredi 27 Juin à 14H00

amphithéâtre Nougaro

Resumé :

When a slender flexible cylinder is placed in flow, it can oscillate. If the structure is placed such that its long axis is in-line with the flow (a purely axial flow case), it undergoes various instabilities including buckling, Hopf bifurcation, torus and period doubling, exhibiting limit cycle, quasiperiodic and eventually chaotic oscillations. The amplitude of oscillations in these cases can be up to a few times the cylinder’s diameter in the transverse direction, depending on the boundary conditions. If the long axis of the cylinder is placed normal to the flow (a purely
cross-flow case), the flexible cylinder undergoes vibrations with an amplitude of around one cylinder diameter (this is known as vortex-induced vibrations). Recent experimental data show signs of quasiperiodic and chaotic-like oscillations in flexible cylinders in cross-flow. If the long axis of the cylinder is placed at an angle with respect to the oncoming flow, the cylinder will behave neither as a pure axial case nor as a pure cross-flow case. In this talk, I will discuss the dynamics of a flexible cylinder in all of these configurations using theoretical and experimental
results.