Effects of wave generation distance in particle-based numerical wave tank on the analysis of overtopping wave energy converters

Abstract

The accuracy of performance assessments for overtopping wave energy converter (OWEC) is significantly influenced by reflected waves. This study evaluates the impact of reflected waves on OWEC performance using environmental data from the coastal region of Ulleungdo. A two-dimensional numerical simulation, based on the Smoothed Particle Hydrodynamics (SPH) method, was conducted to analyze how design variables affect overtopping performance and energy efficiency. Recognizing the overestimation issues in previous research due to the absence of reflected wave considerations, this study integrates updated environmental conditions to mitigate such impacts. The findings indicate that changes to the upper and lower structures in the models resulted in overall energy efficiency variations of approximately 1%, indicating minimal differences. However, significant changes in energy efficiency were observed across individual reservoir levels. Specifically, the energy efficiency of Reservoirs 3 and 4 decreased, while the efficiency of Reservoir 2 increased by an equivalent amount, with the magnitude of variation ranging from 6% to 8%. This study highlights the importance of addressing reflected wave effects in OWEC design, emphasizing the need for three-dimensional simulations and exper-imental validations in future research.