Numerical analysis of the distribution of incident wave energy on an onshore oscillating water column wave energy converter

Abstract

In this study, a numerical analysis to evaluate the energy efficiency of an Oscillating Water Column (OWC) wave energy converter is carried out. The device geometry is based on the pilot plant installed on Pico Island, Azores, Portugal. The methodology consists in calculating the percentage of the incident energy that is distributed along the wave energy conversion. The FLUENT® numerical model, which is based on the Reynolds-Averaged Navier-Stokes (RANS) equations, is used. The Volume of Fluid (VoF) method is employed to take into account the water and air fluids. The case study comprises a flume 10 m deep with an onshore OWC at its end. The distribution of the incident wave energy (1 m wave height with a 9 s period) is determined in terms of reflected wave energy, water column oscillation potential energy, pneumatic energy and energy losses due to viscosity and turbulence dissipations. Results show that the incident wave energy is distributed around 37% for the sum of reflected wave energy and viscosity energy loss, 52% for pneumatic energy and 11% for water column oscillation potential energy.