LBM Simulations for the Head-on Collisions of Vortex Pairs and Vortices-Wall Interactions in Two Dimensions

Vortex dynamics has been studied in two dimensions with lattice Botzmann method for the basic interactions of vortices. With different off-center distances the head-on collisions of two equal pairs of vortices(two dipoles) different regimes have been found: exchanging, merging and diffracting. Meanwhile the interactions of a vortex dipole with solid wall have been also investigated and comparison with existing experiments has been shown certain agreement. More complicated cases for three dimensions are left for future works.