Hydrodynamic performance and power optimization in modular oscillating surge wave energy converters

In this study, we examine the hydrodynamic performance of a bottom-fixed, flap-type Oscillating Surge Wave Energy Converter in a closely spaced modular configuration. Various system configurations with differing module widths are modeled. Hydrodynamic coefficients are determined using Boundary Element Method based on linear wave theory. Regular, head-on waves are employed to drive the oscillators, and the efficiency of each configuration is evaluated through metrics such as Capture Factor, with results validated against similar prior studies. The impact of power take-off damping on system performance is explored, particularly in relation to the multi-degree-of-freedom nature of the system. Viscous effects are incorporated through a linearization approach, and their influence on motion responses and system performance is analysed. The findings indicate that optimal damping strategies from previous research may not maximize power capture for the modular system. As a novel contribution, an optimized modular stiffness configuration is proposed, demonstrating a significant improvement in Capture Factor with minimal radiated power. This stiffness system can function independently or as a coupling mechanism between modules, depending on wave conditions. Finally, we discuss enhancements in capture efficiency and absorption, demonstrating that the proposed modification to system dynamics enables more efficient operation and improved performance of the device.