Vortex dynamics in an electrically conductive fluid during a dipole-wall collision in presence of a magnetic field

We investigate numerically the flow physics generated by the collision of a vortex against a wall in an electrically conductive fluid. Governing magnetohydrodynamic equations are solved by the lattice Boltzmann method. Our findings demonstrate that the presence of a magnetic field modifies significantly the vortex dynamics. Specifically, it exerts a braking effect on the vortex that increases with the magnetic Prandtl number. Our results are linked to the transfer of energy between the velocity and the magnetic fields, as well as to the evolution of their enstrophies.