Maximizing oscillating water column efficiency: The impact of vertical plate and guide vane

This study is centered on improving the hydrodynamic efficiency of a conventional Oscillating Water Column (OWC) that has a rectangular cross-section. The OWC chamber is modified by introducing a centrally installed vertical plate, dividing it into two sub-chambers, and further incorporating a quarter-circle guide vane beneath the vertical plate. Physical experiments are conducted under three scenarios: the conventional single-chamber OWC, the OWC with double sub-chambers separated by a vertical plate, and the OWC with both a vertical plate and a guide vane. Hydrodynamic efficiency is examined across varying Power Take-Off (PTO) dampings, incident wave frequencies, and wave heights. Results demonstrate substantial efficiency improvements with the vertical plate, particularly at lower dimensionless wave frequencies. The guide vane also boosts these benefits by preventing vortex formation due to flow separation, resulting in a total average efficiency increase of 42 %. Visual observations highlight the transition from sloshing to piston-like motion induced by the vertical plate, contributing to increased kinetic energy and improved efficiency. The study highlights that basic but effective modifications can substantially enhance OWC efficiency, suggesting promising directions for the development of wave energy conversion technology.