Experimental study on the performance of a combined comb-type breakwater and wave energy converter device

Reducing the construction costs of wave energy converters is a critical challenge in the development and utilization of wave energy. Integrating wave energy converters with existing breakwaters offers a practical solution. This study investigates the hydrodynamic performance of a comb-type breakwater, which also functions as an oscillating water column wave energy converter. Experiments were conducted under regular wave conditions to examine wave attenuation and air chamber performance. The effects of key parameters, including perforation opening width (0.15 and 0.25 m), opening height (0.20, 0.25, and 0.30 m), opening area (0.03 to 0.75 m2), and air chamber volume (0.063, 0.046, and 0.030 m3), were analyzed. Results indicate that the wave transmission coefficient increases with larger opening widths, decreases with greater air chamber volumes, and is relatively insensitive to variations in opening area. The reflection coefficient increases with opening width, decreases with air chamber volume, and varies significantly with changes in opening area and height across different wave periods. Wave energy conversion efficiency is higher at smaller wave heights, while air chamber energy absorption efficiency is lower under the same conditions. Appropriately increasing the opening width, height, and area enhances both energy conversion and absorption efficiencies. Conversely, increasing the air chamber volume reduces energy conversion efficiency but improves energy absorption efficiency. A trade-off was observed between wave attenuation and energy conversion performance. To balance both functions, the optimal configuration was found to be an opening width of 0.25 m, opening height of 0.30 m, an opening area of 0.075 m2, and an air chamber volume of 0.046 m3.