Systems of reactively loaded coupled oscillating bodies in wave energy conversion

This paper studies systems of coupled oscillating bodies used in wave energy conversion. The objective is to compare devices using a submerged reaction mass with devices where such a mass is on board. Two-degree-of-freedom frequency-domain models based on regular wave excitation are used for this purpose. The optimal reactive and resistive loads and the corresponding oscillation amplitudes and energy absorption capture width ratios are determined approximately. The optimal loads are compared with exact results. Dynamic coupling is found to produce some distinct advantages over single-degree-of-freedom devices. Further, while the system with the submerged mass appears to perform better overall, both are seen to have features that could be advantageous in applications.