The influence of channel walls on flag flutter

International audienceThe effect of confinement of a rectangular channel on the flag flutter instability is investigated, both in terms of waves propagating in the infinite medium (local approach) and in terms of modes in the finite length system (global approach). Using a 1D Euler-Bernoulli model for the plate and a 3D potential flow model for the flow, the problem is solved numerically for various sets of the geometrical parameters to compute the critical velocity for instability as function of the mass ratio. It is found that the proximity of walls parallel and perpendicular the plate affects significantly the plate's dynamics and instability. One main conclusion of this work is that models considering a 2D flow can predict correctly the critical velocity only in specific cases such as large mass ratio, large aspect ratio or very confined plates