Onno Bokhove, Anna Kalogirou, Wout Zweers

We explore extreme nonlinear water-wave amplification in a contraction or, analogously, wave amplification in crossing seas. The latter case can lead to extreme or rogue-wave formation at sea. First, amplification of a solitary-water-wave compound running into a contraction is disseminated experimentally, for small-scale and larger wavetanks. Maximum amplification in our bore-soliton-splash observed is circa tenfold. Subsequently, nonlinear and numerical modelling approaches are developed and validated for amplifying, contracting waves. Amplification phenomena observed have led us to develop a novel wave-energy device with wave amplification in a contraction used to enhance wave-buoy motion and magnetically-induced energy generation. An experimental proof-of-principle shows that our wave-energy device works. Furthermore, we develop a monolithic, mathematical model of wave hydrodynamics, buoy motion and electric power generation by magnetic induction, satisfying one grand variational principle in its conservative limit. Dissipative features, electrical wire resistance and nonlinear LED-loads, are added a posteriori. Preliminary simulations of our simplified (linear) wave-energy model are encouraging. Further highlights discussed are: exact modelling of crossing seas with Kadomtsev-Petviashvilis equation, bore-soliton-splash relevance to devastating Tohoku tsunami run-up in 2011, nonlinear wave-energy optimisation and a steel-soliton-splash artwork. (Note that this is a non-peer reviewed preprint submitted to EarthArXiv.)