Proposal of a novel analytical wake model and array optimization of oscillating wave surge converter using differential evolution algorithm

Abstract

Oscillating wave surge converters (OWSCs) have been extensively used to exploit wave energy. To maximize the energy output from an OWSC array, layout optimizations must be conducted; therefore, an analytical wake model of OWSC is needed for fast optimization iterations. However, no wake model of OWSC and no wake-model-based array optimization approach have been developed. To this end, this study proposed a novel analytical wake model of OWSC. Based on the proposed wake model and differential evolution algorithm, layout optimizations of OWSCs in wave energy farms were performed. To establish a database for deriving the analytical wake model, OWSCs were numerically simulated using the smoothed particle hydrodynamics (SPH) method, where the incoming wave height, damping of the power take-off system, and flap width were varied. The attained analytical wake model could predict the wave height changes in wake regions of OWSCs with an accuracy of 90.0% compared with the numerical SPH results. The optimized OWSC layouts demonstrated that staggered layouts with narrow and wide OWSCs placed in the front and back of wave energy farms, respectively, were economical and appropriate. Furthermore, a simplified guideline was proposed to determine OWSC layouts. Finally, all the codes implemented in this study were open-sourced.