CFD Modelling of OWC Devices for Wave Energy Harnessing

This book chapter is focused on how to study the fluid dynamic behavior of a Wave Energy Converter (WEC) of the Oscillating Water Column (OWC) type by means of Computational Fluid Dynamics (CFD). The U-OWC plant installed in the harbor of Civitavecchia (Italy) is chosen as the case study. The CFD approach is described referring to ANSYS Fluent, release 17.2. The model is mainly oriented to investigate the interaction of single harmonic waves with the OWC device and allows the user to perform a preliminary wave-to-wire energy conversion process analysis. To limit the computational cost, a 2D model is developed. The presence of the Power Takeoff (PTO) system generally breaks the 2D configuration of this kind of device, and here an approach to overcome this problem is described in detail. The solution is the introduction of a porous medium region in the 2D computational domain, which emulates the effect of the PTO system on the fluid dynamic behavior of the flow inside the WEC.