Wave Energy Extraction from an Oscillating Water Column in a Truncated Circular Cylinder

Abstract

Oscillating Water Column (OWC) device is a relatively practical and convenient way that converts wave energy to a utilizable form, which is usually electricity. The OWC is kept inside a fixed truncated vertical cylinder, which is a hollow structure with one submerged open end in the water and with an air turbine at the top. The research adopts potential theory and Galerkin methods to solve the motion of the OWC. Based on the air-water interaction model, optimal OWC design for energy extraction from regular wave is explored.

The hydrodynamic coefficients in scattering and radiation potential are solved using Galerkin approximation. The numerical results for the free surface elevation have been verified by a series of experiments conducted in the University of New Orleans Towing Tank. The effect of geometric parameters on the response amplitude operator (RAO) of OWC is studied and amendment of the equation for evaluating the natural frequency of the OWC is made.

Using the model of air-water interaction under certain wave parameters and OWC geometric parameters, a computer program OWC Solution is developed to optimize the energy output from the system. Optimization results by the program OWC Solution lead to an effective method to design the OWC system.