Rajan, S.N., Karmakar, D. and Guedes Soares, C. (2019), “Influence of damping on the Oscillating Water Column WEC integrated with breakwater”, Advances in Renewable Energies Offshore, Guedes Soares, C., (Ed.), Taylor & Francis, London, UK, pp. 579-587

Oscillating water columns (OWC) are the reliable wave energy converters to absorb the maximum incident wave energy from the ocean waves. These devices make use of the air column under pressure inside the device which oscillates in response to the wave condition for the conversion of ocean energy to electrical energy. As the installation and maintenance of the device as a single, isolated unit is costly, they can be integrated with coastal breakwaters to bring down installation and maintenance cost. The integration of OWC will benefits for the stability of the breakwater also. If wave energy converters like oscillating water column devices are installed in the sloping side of breakwaters, where it is more prone to damage due to the wave action, these devices will absorb the wave energy thus contributing to the stability of the shore protection structures by reducing the incident wave heights. In the present study, the oscillating water column under consideration is integrated with caisson type breakwater. Integration of OWC with breakwater justify the reduction of total expenditure and the easy access to OWC for construction, operation and maintenance. The air column under pressure due to the damping from the PTO device drives the turbine placed at the orifice of OWC. The relationship between the hydrodynamic efficiency of the OWC and the PTO damping is analyzed which would give more precision about efficient wave energy extraction using an OWC. The PTO damping on the chamber is characterized using a linear pressure drop law with the permeability coefficient derived from Darcy’s equation for flow through porous media. An open Computational Fluid Dynamics (CFD) tool, REFF3D, is used for the simulations to analyze the reaction of the OWC under different damping conditions due to the PTO device. Flat bottom and slope bottom configurations are studied and the results are obtained for zero damping, low damping, moderate damping and high damping. The hydrodynamic efficiency for the flat and slope bottom configurations with breakwater are compared to analyze the performance of OWC integrated with breakwater due to the change in the bottom configuration inside the OWC chamber.

If you did not manage to obtain a copy of this paper: Request a copy of this article

For information about all CENTEC publications you can download: Download the Complete List of CENTEC Publications