Numerical investigation on the hydrodynamic performance of a 2D U-shaped Oscillating Water Column wave energy converter

The U-Oscillating Water Column (U-OWC) is a wave energy harvester exploiting the working principle of oscillating water columns for capturing and converting energy from sea waves. U-OWC devices can be integrated into a breakwater to enable wave energy extraction and provide shelter for port activities. In this work, a coupled Smoothed Particle Hydrodynamics (SPH) model was developed and applied to investigate the hydrodynamics of a U-OWC breakwater. The numerical model is validated against the experimental results over a range of regular wave conditions. An extensive campaign of computational tests is then carried out, studying the effects of geometrical parameters on the hydrodynamic performance and wave loading over the U-OWC breakwater. It shows that the geometrical parameters of the U-shape have a significant effect on the air pressure inside the chamber and the load phase difference between the two sides of the lip wall. The minimum load and maximum capture efficiency designs for U-OWC breakwaters cannot be satisfied geometrically at the same time. This demonstrates that it is necessary to consider comprehensively the structural reliability and hydrodynamic performance in the design and construction of a U-OWC breakwater.