FORMATION OF VORTEX MOTION IN THE BULK AND ON THE SURFACE OF VISCOUS LIQUID

Recently it has been demonstrated in 1,2 that waves on the surface of a liquid which propagate at an angle to each other generate vortex motion on the liquid surface. Two perpendicular standing waves form a vortex lattice on the surface of a liquid with spacing equal to the wavelength 2. There are two mechanisms of generation of such vortex motion. In the first mechanism, vorticity on the surface of a liquid is formed due to the Stokes dragSt, in the second one it is formed due to the nonlinear wave interactionE. In a stationary state, vorticity distribution over the surface(x,y,z) is described by a sum of two identical terms 2 differing in the multipliers and does not depend on the viscosity