Inviscid Simulations of Interacting Flags and Falling Sheets

TL;DR

This paper presents inviscid fluid simulations of flexible bodies like flags and falling sheets, demonstrating vortex shedding, buckling, and complex motion patterns such as circling and flapping.

Contribution

It introduces a simulation framework capturing the dynamics of flexible bodies in inviscid fluids, including vortex shedding and interaction effects.

Findings

Flags exhibit synchronous and asynchronous flapping states.

Falling sheets buckle at critical speeds, shedding vortices.

Complex trajectories like circling and quasi-periodic flapping are observed.

Abstract

We present a fluid dynamics video showing simulations of flexible bodies flapping and falling in an inviscid fluid. Vortex sheets are shed from the trailing edges of the bodies according to the Kutta condition. For interacting flags, a sampling of synchronous and asynchronous states are shown. For falling flexible sheets, 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.