Enhancing the energy capture performance of wave energy converters by applying tuned apertures: An experimental and numerical study

The commercialization of wave energy converters (WECs) is hindered by low energy capture efficiency and high costs. This study introduces a novel frequency-control strategy that integrates tuned apertures into the WEC design. By combining experimental investigations with high-fidelity computational fluid dynamics modeling, the hydrodynamic and energy capture performance of the proposed system was systematically evaluated. Experimental results demonstrate that opening apertures extends the system's natural period from 0.7s to 0.8s, significantly enhancing the heave amplitude (up to 32%) and capture width ratio (up to 22%) under low-frequency waves. Furthermore, the nonlinear mechanisms underlying aperture-induced vortex field evolution, formation of internal recirculation zones, and gas-liquid permeation hysteresis effects were elucidated. These analyses explain the intrinsic mechanisms by which these phenomena enhance energy capture in the non-resonant low-frequency range while suppressing response in the resonant region. Under irregular waves, tuned apertures reshape the response spectrum of the WEC to better align with the wave energy spectrum and increase the average power output by 18%. This study confirms that the performance enhancement is frequency-selective, reliant on matching the aperture-tuned natural frequency with dominant wave frequencies, thereby offering a robust, forecast-free strategy for adaptive wave energy conversion.