Abstract
Wave energy, as a clean and abundant resource, offers significant potential for sustainable power. Oscillating Water Column (OWC) is a key technology in this domain. In studies related to OWC, air compressibility can be a significant parameter. This research examines the error caused by neglecting the effects of air compressibility in numerical modeling. To this end, a numerical solution for a 1:10 scaled OWC model was developed based on RANS equations and the Volume of Fluid (VoF) method for free surface water. The wave conditions studied correspond to those in the Caspian Sea. For validation, the pressure within the chamber was compared with experimental results. The results indicated that the error for the incompressible model is 9.89% and for the compressible model is 8.43%. To account for air compressibility effects, a User-Defined Function (UDF) was added to the numerical solution, which adjusts the air density according to isentropic pressure equations. The results showed that considering air compressibility can lead to up to a 5.71% overestimation of the converter’s output power at certain incident wave frequencies. Additionally, at resonance conditions where the incident wave frequency matches the natural frequency of the converter, the effect of air compressibility is minimized.