Performance of Multi Chamber Oscillating Water Columns: Effects of Chamber Configuration and Power Absorption

Oscillating Water Column (OWC) is a promising green energy technology for wave energy conversion, accounting for 26.79% of global wave energy converter applications. This study investigates the hydrodynamic and aerodynamic performance of multi-chamber OWC systems with variations in chamber inclination angles (0°, 20°, and 40°) and the number of chambers (2, 3, and 4). Computational Fluid Dynamics (CFD) simulations were performed using the Reynolds-Averaged Navier-Stokes (RANS) equations and the RNG turbulence model to analyze flow characteristics under regular wave conditions. Key parameters evaluated include free surface elevation, air pressure, air velocity, power distribution, and power absorption. Results indicate that the highest free surface elevation (1.545 m) occurred in a 4-chamber configuration with a 0° inclination. The maximum air pressure (774,804 Pa), air velocity (36.356 m/s), and power distribution (23.58 kWh) were found in a 3-chamber system with a 40° inclination. Meanwhile, the highest total power absorption (42.79 kWh) was observed in a 4-chamber system with a 40° inclination. The 4-chamber configuration with a 40° inclination showed the best performance, achieving 42.79 kWh of power and 0.86 efficiency—outperforming 3-cahmber and 2-chamber setups by 52% and 77%, respectively. Generally, configurations with more chambers resulted in greater power absorption but lower individual pressure and velocity peaks. Increased inclination tends to reduce water surface oscillation. These findings provide insights for optimizing multi-chamber OWC design for improved wave energy capture.