Vortex formation near protuberances on a solid surface and the structure of the Ginzburg-Pitaevski equations

It is shown that when a superfluid liquid flows around protuberances or corners on a solid boundary then areas analogous to local supersonic zones in a subsonic flux are formed, where hydrodynamical perturbations of the surfaces of discontinuity may initiate the nucleation of vortices. (Auth.)