Three-dimensional Numerical Simulation of Airflow in Oscillating Water Column Device

Abstract

Lee, K.H. and Kim, T.G., 2018. Three-dimensional Numerical Simulation of Airflow in Oscillating Water Column Device. In: Shim, J.-S.; Chun, I., and Lim, H.S. (eds.), Proceedings from the International Coastal Symposium (ICS) 2018 (Busan, Republic of Korea). Journal of Coastal Research, Special Issue No. 85, pp. 1346–1350. Coconut Creek (Florida), ISSN 0749-0208.An Oscillating Water Column (OWC) is a wave energy converting technology that uses the compressed and decompressed airflow induced by the vertical oscillations of water column inside the chamber as a driving force of an airflow turbine. In this study, three-dimensional numerical simulations of a bottom-fixed OWC are performed to understand the interaction of an OWC device with regular waves. The open-source CFD model REEF3D is used, which is able to consider immiscible two-phases (air and water) using the Reynolds-averaged Navier-Stokes equations. The simulation capability of REEF3D is validated by comparison with experimental data for wave deformations caused by the OWC and air-flow fields and the airflow velocity in the chamber. The numerical results revealed that the CFD numerical tool REEF3D can successfully simulate wave deformations caused by wave-OWC interactions, and directly estimate an air velocity inside the chamber. In addition, it was found that a phase difference occurs between time series of free surface evolution and air velocity evolution.