Blind test comparison of wave–structure interactions: A non-linear Froude–Krylov modelling approach

One of the essential stepping stones for reaching economic viability and industrial feasibility of the wave energy conversion sector is the effectiveness of the device design, which is dependent, among others, to the accuracy of mathematical models used for development. Despite being more than 45 years old, modelling is not mature yet and there is still a clear lack of standardisation of modelling techniques, and a need for increasing confidence in hydrodynamic models. The objective of the Collaborative Computational Project in Wave Structure Interaction is to critically compare and evaluate various different modelling techniques, under the same shared experimental conditions, and using clearly pre-defined metrics. This paper details a contribution implementing, in a computationally efficient way, non-linear Froude–Krylov forces and non-linear kinematics, with the goal to define a medium–high fidelity model, able to compute at a small fraction of the computational time typically required by fully non-linear models. The case study considers survivability-like wave conditions, represented by three steep focused waves, particularly challenging to be modelled using potential theory-based mathematical models. Despite a poor representation in pitch/surge, a good agreement with experimental heave response and mooring load is found, at small computation time, close to real-time computation.