Model Validation and Hydrodynamic Performance of an Oscillating Buoy Wave Energy Converter

Abstract

An oscillating buoy (OB) could function simultaneously as a wave energy converter and a breakwater. In this work, a numerical study is conducted to assess the ability of the buoy to perform both aforementioned tasks by quantitatively and qualitatively assessing its hydrodynamic performance. The computational fluid dynamics solver used for the numerical study is ANSYS Fluent, which uses Reynolds-averaged Navier-Stokes equations and Volume of Fluid method for the design and simulation of the numerical model, which consists of a rectangular OB that floats on the surface of a numerical wave tank. First, a total of six independent studies, namely the time, meshing, damping, overset geometry, flow viscosity, and spatial studies, were conducted for validation purposes. Second, calculation and analysis of the heave and transmission coefficients and vorticity magnitude were conducted to assess the hydrodynamic performance. Results of independent studies show cases with a high degree of accuracy to the experimental model, whereas results for hydrodynamic performance show a generally increasing heave movement of OB and transmission coefficient across the range of wave periods studied. Meanwhile, the vorticity magnitude flow fields show at least two vortices for all wave periods studied, except for the shortest two wave periods.

Keywords

• computational fluid dynamics
• wave energy converter
• oscillating buoy
• breakwater
• hydrodynamic performance