Numerical simulation is an essential tool to predict ocean conditions at tidal energy sites. Knowledge of flow velocity, water level and wave conditions are required for site selection, resource quantification and project planning. Studies for individual tidal energy sites have shown that wave effects can potentially reduce the average tidal energy potential by 8-15%. These studies have been performed for individual sites, rather than larger, regional models to inform the initial site identification.
Coupling of hydrodynamic flow and wave models is often undertaken to improve the accuracy of outputs from both models. Fully coupled simulations require considerable information to be passed between the individual flow and wave models at each computational time-step. This is considerably more computationally expensive and increases model run-times significantly. This work discusses the question of whether operating the flow and wave simulations in a fully coupled mode provides significant improvement over running the models separately.
A large regional coupled flow-wave model has been established covering the English Channel using the Delft3D Flexible Mesh hydrodynamic package coupled with SWAN (D-WAVE). This work presents a comparison study of the models when run as a fully coupled simulation and as a one-way offline simulation. Output is presented at several sites where the potential for tidal energy is considered. The statistical analysis of the differences is also discussed. This paper will be of interest to researchers and practitioners involved in tidal energy resource modelling and site identification and planning.