A novel wave-energy device with enhanced wave amplification and induction actuator

Bokhove, Onno; Kalogirou, Anna; Henry, David; Thomas, Gareth P

Abstract

A novel wave-energy device will be presented. Both a preliminary proof-of-principle of a working, scaled laboratory version of the energy device will be shown as well as the derivation and analysis of a comprehensive mathematical and numerical model of the new device. The wave-energy device includes a convergence in which the waves are amplified, a constrained wave buoy with a (curved) mast and direct energy conversion of the buoy motion into electrical power via an electromagnetic generator. The device is designed for use in breakwaters and it is possible to be taken out of action during severe weather. The idea of wave-focusing in a contraction emerged due to our work on creating and simulating rogue waves in crossing seas, including a "bore-soliton-splash". Such crossing seas have been recreated and modelled in the laboratory and in simulations by using a geometric channel convergence. The new design is a deconstruction of elements of existing wave-energy devices, such as the TapChan, IP wave-buoy and the Berkeley Wedge, put together in a different manner to enhance energy conversion and, hence, efficiency. The mathematical and numerical modelling is also novel. One monolithic variational principle governs the dynamics including the combined (potential-flow) hy-drodynamics, the buoy motion and the power generation, to which, a posteriori, the dissipative elements such as the electrical resistance of the circuits, coils and loads have been added. The numerical model is a direct and consistent discretisation of this comprehensive variational principle. Preliminary numerical calculations will be shown for the case of linearised dynamics; optimisation of efficiency is a target of future work.

Citation

Bokhove, O., Kalogirou, A., Henry, D., & Thomas, G. P. (2019). A novel wave-energy device with enhanced wave amplification and induction actuator

• Conference Name: 13th European Wave and Tidal Energy Conference
• Start Date: Sep 1, 2019
• End Date: Sep 6, 2019
• Acceptance Date: May 24, 2019
• Publication Date: Sep 6, 2019
• Deposit Date: May 29, 2019
• Keywords: Index Terms-water-wave focussing; wave-energy buoy; electro-magnetic generator; monolithic variational princi- ple; finite-element modelling
• Public URL: https://nottingham-repository.worktribe.com/output/2105639
• Related Public URLs: https://ewtec.org/conferences/ewtec-2019/