Falling Flexible Sheets

We present a fluid dynamics video showing simulations of flexible bodies falling in an inviscid fluid. Vortex sheets are shed from the trailing edges of the bodies according to the Kutta condition. The basic behavior is a repeated series of accelerations to a critical speed at which the sheet buckles, and rapidly decelerates, shedding large vortices. Examples of persistent circling, quasi-periodic flapping, and more complex trajectories are shown.