A comparative investigation of lip wall geometry on OWC efficiency under varying wave steepness

The oscillating water column (OWC) is a widely used technology for harnessing ocean wave energy in coastal structures. This study presents a comparative numerical analysis of OWC systems with varying lip wall angles ( β = 0°, 30°, 45°, 60°, and 75°) using ANSYS FLUENT within a three-dimensional numerical wave tank. The governing equations were solved through the Finite Volume Method with turbulence modeled by the k - ε model. Simulations were performed under five different wave conditions ( H i /λ = 0.02–0.05) and five orifice ratios ( ε = 0.4%–1.3%), maintaining a constant relative opening ( σ = 75%). Model validation against experimental data confirmed the reliability of the numerical approach. Results revealed that the lip wall angle significantly influences OWC performance, with the β = 60° configuration achieving the highest hydrodynamic efficiency. The inclined lip wall enhanced energy capture compared to the conventional vertical design. These findings provide valuable insights for optimizing the structural design and deployment of OWC systems in the marine renewable energy sector, contributing to improved energy conversion efficiency and sustainable coastal engineering solutions.