The OVI project is a collaboration between me at Bristol University and Alison Hunt, Geoff Bullock and Ravi Jayaratne at Plymouth University. We are studying violent wave impacts and their overtopping over vertical and sloping walls. We make use of focused wave groups on the experimental side and compressible Euler equations plus Navier Stokes modelling on the numerical side.
Nonlinear waves with vorticity
Inclusion of vorticity in Boussinesq models.
Many water wave problems can be solved with good accuracy using potential flow theory. This simplifies the computational work considerably. For water waves, the socalled Boussinesq type models have shown great success in accurately modelling highly nonlinear and dispersive wave motion, yet reducing the original 3D problem to a 2D one.
Most Boussinesq models, however, are derived under the assumption of potential flow. Hereby, the effect of a shear current cannot be modelled. Also, the production of vorticity in breaking waves is not modelled.
In this project with Per Madsen and Hemming Schäffer, vorticity effects are included into the class of highly accurate Boussinesq models, developed at DTU over the last decade.
Impacts from focused wave groups on monopiles
Monopile foundations for offshore wind turbines are subject to the harsh environment at sea. In this project extreme wave impacts are modelled in terms of focused wave groups. Wave components from a JONSWAP spectrum are linearly superimposed and matched in phase to hit the structure just at the time of breaking. The modelling is done with the OpenFOAM CFD solver.