Numerical simulation of a Rayleigh-Taylor instability without surface tension

Numerical simulation of a Rayleigh-Taylor instability without surface tension. The interface separating the two fluids is represented a collection of edges of the elements of the mesh, thus requiring an ALE formulation. The domain is remeshed when the error level (estimated using the technique of Zienkiewicz & Zhu) is higher than a prescribed threshold.
From left to right: interface, velocity, vorticity, mesh