Generation of stripe-like vortex flow by noncollinear waves on the water surface

We have studied experimentally the generation of vortex flow by gravity waves with a frequency 2 . 34 Hz excited on water surface at an angle θ = arctan ( 3 / 4 ) ≈ 6 ∘ to each other. The resulting horizontal has stripe-like spatial structure. width stripes L π k sin is determined wave vector and between them, length limited system size. It was found that vertical vorticity Ω current fluid proportional product amplitudes, but its value much higher than corresponding Stokes drift it continues grow time even after motion reaches stationary regime. demonstrate measured dependence t can be described within recently developed model takes into account Eulerian contribution generated effect contamination. This contains free parameter describes elastic properties contaminated surface, we also show this in reasonable agreement decay rate waves. • Crossed generate streaming currents owing hydrodynamic nonlinearity. structure coincides drift. Streaming are stronger sufficiently long times. Surface contamination modeled presence thin insoluble liquid film. film intensifies increases damping.