ABSTRACT
A novel coupled-mode system is derived for water waves propagating in variable bathymetry regions. The present model includes also scattering effects from inhomogeneous currents. The analysis is based on Euler equations in conjunction with a velocity-based formulation. The vertical expansion of the velocity field is based on a local mode expansion having the property to converge rapidly and satisfy the field equations along with the boundary conditions. The present model extends previous developments for irrotational waves based on a potential formulation presented by Belibassakis et al (2017), supporting the treatment of vorticity effects on the wave field. The dispersion characteristics of the system are studied, and examples are presented illustrating the applicability of this model to various interesting cases of wave-seabed-current interaction.
