Abstract
Motion of an interface is considered between two infinite layers of uniform vorticity in two-dimensional flow of inviscid fluid. The vorticity jumps at the interface but the velocity is continuous to inhibit the Kelvin-Helmholtz instability. The dynamics of the interface is described with an extention of Birkhoff equation for an irrotational perturbation. Fully nonlinear behaviors are studied by numerical simulations based on the point-vortex method. For large enough disturbances, “filaments” are formed as in the case of Contour Dynamics of finte vorticity regions. The curvature grows appoximately exponentially with respect to time and the well-posedness of the problem is suggested.
