Vortex dipole collision with a sliding wall

The collision of a dipolar vortex with a sliding wall is investigated numerically. Previous studies have shown that perpendicular vortex collisions with fixed walls may lead to a rebound of the primary dipole during which the symmetry of the vorticity field with respect to the dipole's axis is preserved. However, a wall sliding tangentially breaks this symmetry, leading to distinctive flow regimes for different wall speeds. The conditions for which the transition between these two regimes occur are studied, both numerically and analytically, in terms of the wall speed and the Reynolds number of the dipolar flow. (paper)