Vortex simulations of impulsivelyaccelerated unstable interface

The point vortex method is applied to simulate the motion of an unstable interfacedriven by an impulsive force. The numerical results from the vortex method agree well with previous numerical results and theoretical models. We study various aspects of the dynamics of unstable interfaces for the case of infinite density ratio. It is shown that the spike velocity converges to an asymptotic limit that depends on the initial amplitude and velocity, while the bubble velocity decays to zero. We also find that the growth rates of bubbles and spikes at late times are slower for larger initial amplitude.