High-fidelity numerical investigation of OSWEC: Effects of turbulence models, varying incident wave angle and irregular waves

Presenter: Minge Jiang, Mechanical Engineering

Authors: M. Jiang, D. Tafti

Abstract: The oscillating surge wave energy converter (OSWEC) is a promising design for extracting ocean wave power, owing to its simple geometry and high capture width ratio (CWR). In this work, we employ high-fidelity computational fluid dynamics (CFD) in OpenFOAM to investigate a rectangular-flap OSWEC under various conditions: different Reynolds- Averaged Navier-Stokes (RANS) turbulence models, varying incident wave angles, and directional irregular wave fields. We first validate the CFD model then assess the performance of different RANS formulations. While the turbulence models produce comparable free surface elevation (FSE) and rigid-body responses, the standard k-ε and k-ω SST models exhibit slight overdamping of the fluid field and wave, whereas the buoyancy-modified k-ω SST formulation notably enhances numerical stability and efficiency. We further demonstrate that increasing the wave heading angle systematically reduces flap rotation and CWR, following a cosine-squared dependence. This angle sensitivity is strongly influenced by the flap width-towavelength ratio, with performance improving as the ratio decreases. Finally, simulations under irregular waves show that using regular representative waves can significantly overestimate OSWEC performance compared to irregular seas.