Dynamics and instability of a shielded vortex in close proximity of a wall

We have investigated the dynamics of a shielded vortex kept in stagnant fluid, in front of plane wall at different heights. This placement instantaneously creates an unsteady boundary layer over the wall and the free vortex starts translation and rotation. Present study focuses not only on the dynamics of the free vortex and the underlying unsteady boundary layer, but a major aim is to explain various instabilities suffered by these two elements. Unlike other works reported on this topic, present computations did not encounter any singularities, which were identified as the harbinger of transition to turbulence. Present simulations are performed over significantly long times, due to the use of high accuracy dispersion relation preserving scheme and multi-dimensional filter.