Abstract
The development path of a wave energy device from concept to full-scale device is comprised typically of a numerical study and experimental modelling at a number of scales. Numerical models based upon Boundary Element Method (BEM) codes are widely used within the offshore industry and have been validated for fixed Oscillating Water Column (OWC) devices of shoreline type, providing confidence in their use. However, as OWC technology develops and devices are designed for offshore environments, validation of numerical codes for floating OWCs is required. In comparison with characteristic offshore structure design, which aims to minimise motion, wave energy device design has the goal of energy extraction. This may require significant motion, balanced by the power take-off mechanism, and therefore necessitating additional validation for the purpose.
The aim of this paper is to provide a preliminary assessment of the validity of employing a BEM code to predict the displacement and associated hydrodynamic properties of a simple floating undamped OWC in the form of a hollow vertical circular cylinder. Predictions obtained from the WAMIT code are compared with experimental measurements at selected frequencies and with increasing wave amplitude. An investigation of the agreement for predicted and measured pressures is also undertaken.