D1.3 Nearshore Wave Forecasting Model – Theory and User manual

Renewable energy is a growing market with most of its productivity attributed to solar and wind power. Marine renewable energy has been widely associated with tidal power plants, whereas wave energy remains a relatively small market with enormous potential. Many recent designs of wave energy converters (WEC) – such as the MegaRoller concept - were developed for shallow coastal waters. Consequently, optimisation of the design and assessment of potential deployment sites for these WEC greatly depend on a detailed understanding of the nearshore wave field in dependence of the characteristics of incoming swells, tide, and local bathymetry. To understand the dynamic coastal system, researchers and engineers show an increasing interest in phase-resolving numerical models. Especially, models built around Boussinesq-type equations have developed into powerful tools for coastal engineering as well as for assessment studies of coastal hazards and marine renewable energy. This theory and user manual describes the numerical code BOSZ (Boussinesq Ocean & Surf Zone model) for the solution of a set of Boussinesq-type equations and helps future users to work through particular examples and benchmarks to become familiar with the code. The model provides accurate and robust solutions in a reasonable amount of time for a wide range of nearshore wave processes, which include wave propagation, transformation, breaking and run-up on land. Due to the phase resolving nature of the model, secondary processes such as wave set-up, recirculation, and generation of infra-gravity waves are well captured within the solution structure. The BOSZ model can be used to facilitate WEC designs and to assess potential deployment sites. In particular, and as part of the MegaRoller project, the BOSZ model will support the characterisation of WEC deployment site, which ca inform the definition of the critical design situations to consider as part of the design process (e.g. by defining normal and extreme sea states), or the definition of a wave-by-wave prediction of the wavefield approaching the device, enabling a real-time adjustment of the control algorithm to optimise the power-take off (PTO)