Vortex-induced wavefront dislocations in water surface waves

Abstract

We investigate wavefront dislocations arising from the interaction between a wave vortex and an incident surface wave. The system is modeled within linear water wave theory, combining a vortex lattice formed by orthogonal standing waves with a propagating incident wave of tunable amplitude. Wavefront dislocations are identified through the amplitude and phase of the vertical velocity field obtained via a temporal Hilbert transform. To characterize the induced flow, we compute the Stokes drift velocity, and the spin derived from the local particle polarization. Numerical results show that increasing the incident wave amplitude leads to a reorientation of particle trajectories and a transition in the spin distribution. The probability density functions of the spin components and spin angle reveal a quadratic scaling with the driving amplitude and an alignment of the spin as prescribed by the incident wave direction. These findings demonstrate controllable coupling between vortex-induced topology and wave-driven transport in hydrodynamic systems.