This work follows the evolution of a thin shell driven out by a fast stellar wind. The simulation shown here assumes an isothermal EOS with Mach=10 for both the forward and reverse shocks. The color represents the transverse velocity. The initial perturbation is a sinusoidal variation in the radial motion of the shell at the level of 1% the sound speed.
The plot below shows the growth of the instability as tracked by the kinetic energy in the transverse direction.
