Zalesak's rotating sphere test case

The Zalesak's test case is a common benchmark to evaluate the reconstruction of the interface while the Zalesak sphere is rotating. The background flow is imposed with no need of solving the Navier-Stokes equations. As can be seen in the animation and despite the coarse mesh used on this test case, our moving mesh methodology keeps the interface sharp and with minimal numerical diffusion after many rotations. The red color represents the sharp interface (triangular surface) and the blue stands for the outer mesh (tetrahedrons). The green color is due to the interpolation of the rendering program Paraview.