Overview |  Applications | Scientific References


REEF3D::FNPF is a fully nonlinear potential flow model. The starting point for this model are the unique characteristics of the Norwegian coast: The water depth changes rapidly from deep to shallow water, the coastline is highly irregular and an immense number of small islands complicate meshing. REEF3D::FNPF is tailor-made to incorporate solutions to the Norwegian coastal features, and consequently the model can be used for wave propagation from deep to shallow water while taking care of complex coastlines in an easy to use way. In addition, REEF3D::FNPF has proved to serve as an highly accurate and efficient tool to generate typical 3-hour sea states used for designing offshore and coastal structures. Here, the selected numerical approach has shown to be so robust that extreme sea states with steep nonlinear waves including breaking wave kinematics can be handled. Up to now, REEF3D::FNPF has been used for a range of coastal and offshore industry projects. The unique characteristics of REEF3D::FNPF are:

  • High-order discretization in space (5th-order WENO) for the free surface boundary conditions
  • High-order discretization in time (3rd-order TVD Runge-Kutta)
  • Full Parallelization with domain decomposition and MPI
  • Robust and accurate breaking wave model
  • Coastline algorithm for efficient inclusion of complex topographies
  • Wave propagation from deep water to shallow water
  • Geometric multigrid preconditioned CG-solver (hyper) for efficient solution of the Laplace equation
  • Varying bathymetry with geometry input form DIVEMesh
  • Hydrodynamic coupling to REEF3D::CFD


Coastal Wave Modeling: Bjørnafjord

Modeling of incoming swell waves at Bjørnafjord, Norway using the three-dimensional fully nonlinear potential flow model REEF3D::FNPF in a 35km x 45km domain. As research funded by the ferry-free E39 project ( the new phase-resolved wave model REEF3D::FNPF was developed with a focus on the special Norwegian coastal conditions, i.e. deep water, strongly varying bathymetry and a very irregular coastline.

Coastal Wave Modeling: Sulafjord

REEF3D::FNPF for phase-resolved swell modeling for deep water waves transitioning to intermediate and shallow water and back to deep water conditions inside the Fjord. Domain size: 25km x 16km

Deep Water Wave Modeling: Short Crested Waves

Sea States: 3-hour Irregular Wave Modeling

Norwegian Shelf Modeling

Scientific References

a selection of relevant papers covering the different aspects of REEF3D::FNPF, the collection of all papers including post-prints can be found under Publications

Wang W., Pakozdi C., Kamath A., Fouques S., Bihs H. (2022)
A Flexible Fully Nonlinear Potential Flow Model for Wave Propagation over the Complex Topography of the Norwegian Coast, accepted to Applied Ocean Research, download pdf

Bihs H., Wang W., Pakozdi C., Kamath A. (2020)
REEF3D::FNPF – A Flexible Fully Nonlinear Potential Flow Solver, Journal of Offshore Mechanics and Arctic Engineering, Vol. 142, Nr. 4, DOI: 10.1115/1.4045915download pdf.

Wang W., Kamath A., Pakozdi C., Bihs H. (2020)
A comparison of different wave modelling techniques in an open-source hydrodynamic framework, Journal of Marine Science and Engineering, Vol. 8, Issue 7, Nr. 526, DOI: 10.3390/jmse8070526, download pdf.