Numerical simulation of a full spine of Edinburgh Duck modules in uni- and multi-directional irregular wave climates, with a view to design optimisation

Long, flexibly-jointed spines of Edinburgh Duck modules have the potential to enable the extraction of a large proportion of the wave energy from our seas and oceans. It is well-known that the ‘duck’ shape is able to efficiently absorb wave energy, and that jointed but controlled interconnections between ducks as part of a full spine can also benefit the performance. However, in order to progress further towards achieving optimal performance in real wave climates, a greater understanding of the significance of the spine configuration and scale, spine orientation, and directional, irregular wave conditions is required. By using an efficient hydrodynamic model of a ten-duck spine in conjunction with a constrained frequency-domain control strategy, this paper investigates the effects of the above factors on device performance (as a function of power extraction) in uni- and multi-directional versions of an irregular wave climate. A series of inferences are drawn from the simulations and discussed with regards to informing the direction of future duck spine designs. •An efficient hydrodynamic model is applied to a long spine of Edinburgh Ducks.•A constrained form of complex conjugate control is utilised.•Power extraction in uni- and multi-directional seas is predicted.•The effects of spine scale, spine orientation and wave spreading are investigated.•The results build towards optimisation of the system design.