This is a tough one! So far:

• Boundary conditions are a mixture of (anti-) symmetric conditions for omega
• Periodic boundaries are possible, but need further effort (with unknown result)
• Generation of vortex tube centre lines: done
• Radius of each tube is r=2/3, but then they will overlap (await answer from Tobias)
• Tubes need to be filled with particles, function depending on r: Tobias

Open questions:

• Open boundaries?
• Remeshing required/mandatory or to dissipative?
• Remeshing with a non-constant mesh-size required for finer resolution?