The experimental and theoretical evaluation of a twin-flap wave-energy absorbing device

Abstract

A series of model experiments with a twin-flap wave-energy absorbing device is described, and the results compared with numerical predictions based on theoretical work reported by Srokosz and Evans (1979). Measurements were made of absorption efficiency, flap motion responses, and total flap forces (mooring forces), all with the supporting structure held fixed, with normal wave encounter. Both 2-D and finite-length flap experiments were conducted.Generally, fair agreement was obtained between theory and experiments with regard to efficiency vs wavenumber and applied damping coefficient was generally matched by apparent from these experiments. Maximum efficiencies approaching 100% (as predicted analytically) were confirmed by experiments. Further, the predicted behavior of curves of efficiency vs wave number and applied damping coefficient was generally matched by experimental results.Results for flap motion responses and forces showed good agreement with theory.Some basic conclusions are drawn with regard to practical design and economic considerations for a twin-flap power generating system.