Multi-Objective Evolutionary optimisation of the geometry of a class of controlled wave energy converter

Concerns over climate change and energy security help motivate research into wave energy converters (WEC). Two WEC topologies have shown particular promise and many proposed devices rely on these forms, namely the heaving buoy and the bottom hinged surging flap. It can be shown that to achieve resonance a heaving point absorber requires a diameter that is much larger than practical. By contrast, bottom hinged flaps are generally smaller, hence many hinged flap devices are non resonant. This paper proposes a hybrid of these two topologies, in the form of an off-set hinged flap. The exact form is determined using a novel Multi- Objective Evolutionary Algorithm. The latter has been developed by the authors to address difficult discontinuous optimisation problems like this. The device volume is minimised, whilst simultaneously maximising power capture under both active and passive control.