Boundary conditions for modeling scattered wave field around floating bodies in elliptic wave models

•Presentation and validation of a novel numerical method for modeling the scattered wave field around floating bodies.•Novel boundary conditions for elliptic wave models.•Simulation of large-scale interaction between waves and floating objects over mildly variable bathymetry.

This paper presents a new methodology to reproduce the interaction between waves and floating objects over mildly variable bathymetry. The elliptic mild slope equation solves the fluid velocity potential over a domain, which does not include the near field around each object. The waves scattered by the floating bodies are considered by means of boundary conditions at the edges of the near field areas. The coefficients of these boundary conditions are obtained nesting the solution of a near field three dimensional solver with the elliptic model solution. Comparison with a 3D numerical model, which solves the potential flow field over the whole domain, is used to validate the proposed approach. An example of application to reproduce the wave field around an array of wave energy converters is presented.