Parametric study of the performance of an annular water wave concentrator

The dispersed nature of ocean wave energy distribution often leads to uneconomical wave energy exploitation when conversion devices are deployed only at certain locations. Inspired by the metamaterial concentrator for electromagnetic waves, an annular water wave manipulator has recently been proposed to amplify wave heights in a specific area. A computational fluid dynamics model is developed to investigate the wave evolution around this device, with the numerical predictions compared well with the experimental data. The wave energy concentration performance of the device is systematically analyzed, considering various structural designs, wave frequencies, water depths, and wave heights. The findings confirm the significant increase in wave heights within the concentrator, reaching up to two times the incident wave height in both baffled and unbaffled configurations, as a result of wave refraction and superposition. The effective channeling effect of the guiding baffles enables both the energy concentration within the concentrator and the invisibility downstream of the concentrator. The baffled design produces superior amplification as the nonlinearity of the incident wave increases.