3D vortex field

3-dimensional vortex field test case. This particular benchmark tests extensively the remeshing methodology implemented in our CFD code. The test consists in applying a 3d vortex field on a sphere which will be complete distorted in t=0.5T, where T is the total time of the simulation. From t=0.5T to t=T, the vortex field is reverted and the original sphere shape is thus expected. The characteristic mesh length is L=1/50. The literature shows equivalent result using a different approach for mesh length L=1/256, which proves that the proposed remshing method is accurate.