REEF3D::NHFLOW

Overview |  Applications

Overview

REEF3D::NHFLOW is a three-dimensional non-hydrostatic wave model. This model is implemented in the open-source hydrodynamics framework REEF3D. It uses a Godunov-type scheme for shock-capturing properties, albeit with WENO flux reconstruction. In order to achieve good dispersion characteristics, a pressure correction. As part of the REEF3D framework, MPI parallelization, hypre’s multigrid solvers and high-order finite difference WENO discretization methods are readily available In contrast to m the existing fully-nonlinear potential flow solver FNPF, the new model includes the capability to model the dynamic wetting and drying processes in the swash zone.

  • 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 waves through shock-absorbing solver
  • Wetting and drying algorithm for complex coastlines
  • 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

Applications

Coastal Wave Modeling: Baltic Coast at Narva-Jöesuu (Estonia):

Coastal Wave Modeling: Nazaré, Portugal

REEF3D::NHFLOW for phase-resolved swell modeling for deep water waves transitioning to intermediate and shallow water towards Praia do Norte, Nazaré. The submarine Nazaré Canyon focuses the swell waves towards the cliff with the Fort of São Miguel Arcanjo. Domain size: 11km x 17km

Scientific References

Bihs H., Wang W.W. (2025)
REEF3D::NHFLOW – A High-Performance Non-Hydrostatic Solver for Coastal Wave Propagation, Coastal Engineering, , Vol. 202, Nr. 104819, DOI: 10.1016/j.coastaleng.2025.104819, download pdf.

Bihs H., Ehlers R., Wang W. (2026)
A Shock-Absorbing Non-Hydrostatic Solver on σ-Grids for Wave Modeling Over Complex Bathymetry, Vol. 148, Nr. 011902, Journal of Offshore Mechanics and Arctic Engineering, DOI: 10.1115/1.4068917, download pdf.