Tuesday 10 Mar 2020: Wave amplification phenomena and a novel wave-energy converter
Dr Anna Kalogirou - University of Nottingham
Harrison 103 13:30-16:30
We explore extreme water-wave amplification in crossing seas, which can lead to the formation of rogue waves at sea. We have recreated and modelled such crossing seas experimentally and in simulations by using geometric channel convergence. First, amplification of a solitary-water-wave compound running into a contraction is disseminated experimentally. In further experiments, a bore-soliton-splash is observed with approximately tenfold maximum wave amplification. Subsequently, mathematical and numerical modelling approaches are developed and validated for amplifying nonlinear waves. These amplification phenomena observed have led us to develop a novel wave-energy device with wave amplification in a contraction used to enhance wave-activated buoy motion and magnetically induced energy generation. A laboratory proof-of-principle shows that our wave-energy device works. Most importantly, we develop a novel wave-to-wire mathematical model of the combined wave hydrodynamics, wave-activated buoy motion and electric power generation by magnetic induction, from first principles, satisfying one grand variational principle in its conservative limit. Dissipative features, such as electrical wire resistance and nonlinear LED loads, are added a posteriori. New is also the intricate and compatible finite-element space-time discretisation of the linearised dynamics, guaranteeing numerical stability and the correct energy transfer between the three subsystems. Preliminary simulations of our simplified and linearised wave-energy model are encouraging and involve a first study of the resonant behaviour and parameter dependence of the device.