An impulse-based approximation of fluid motion due to boundary forces

The motion of an incompressible, inviscid fluid in a region surrounded by a massless, elastic membrane can be approximated by transmitting the effect of the boundary forces to the fluid through vortex dipoles. We present a Lagrangian numerical method for approximating this motion based on the impulse (a.k.a, magnetization) variables introduced by Buttke. In particular, we explain the correspondence between impulse variables and vortex dipoles with a prescribed dipole moment. Numerical examples that illustrate the application of impulse variables in this context are given. (C) 1996 Academic Press, Inc.