Extreme Loading on Wave Energy Converters

 

Dr Matt Folley
Dr Paul Lamont-Kane
Alan Mc Kinley

 

 

 

 

 

 

One major difficulty in the design of full scale WECs is the need to design for two conflicting design criteria. In one instance devices must be designed to couple heavily to the incident water waves resulting in the efficient extraction of energy in small to moderate sea states. However, devices must also be capable of surviving the harshness of the much less frequent extreme seas. The danger is that the added cost of design for survivability increases the cost of energy produced to the point whereby wave energy is not commercially competitive.

Here at Queen’s we have been looking into the extreme wave loading of pitching flap-type WECs, often referred to as Oscillating Wave Surge Converters (OWSCs). For large, buoyant, surface-piercing OWSCs such as the Aquamarine Power Oyster device the predominant impulsive loading mechanism is slamming, a phenomenon where the device gets fully submerged by a passing wave crest and upon its release gets accelerated into the oncoming wave trough as outlined in the images below.

The aim of the present course of research is to determine the hydro-mechanical couplings driving the slamming phenomenon and to better inform the future design of OWSCs through a phenomenological investigation of the design space. The research is conducted primarily through physical wave tank testing completed here at QUB and is supplemented by CFD analyses completed using OpenFOAM.

For more information please contact Dr. Paul Lamont Kane.

 

Link to Videos on Youtube

Slamming of the full scale Oyster 800 prototype in extreme sea states

Wave tank testing of OWSC slamming

 

Publications

Preliminary Development of a Pseudo-3D Testing Technique for the Prediction of Extreme Loads on an Oscillating Wave Surge Converter, McKinley, A., Lamont-Kane, P., Henry, A., Folley, M., Nicholson, J., Whittaker, T., Elsaesser, B., Paper presented at 3rd Asian Wave & Tidal Energy Conference, Singapore, 2016.

Extreme Loads on an Oscillating Wave Surge Converter, Lamont-Kane, P., McKinley, A., Henry, A., Nicholson, J., Folley, M. & Elsäßer, B., Paper presented at 11th European Wave & Tidal Energy Conference, Nantes, France, 2015.

The Vertical Distribution and Evolution of Slam Pressure on an Oscillating Wave Surge Converter, Henry, A., Abadie, T., Nicholson, J., McKinley, A., Kimmoun, O. & Dias, F.,  Paper presented at ASME 2015 34th International Conference on Ocean, Offshore and Arctic Engineering, St. John's, Canada, 2015.

The structural response of an oscillating wave surge converter to wave slamming, McKinley, A., Henry, A., Nicholson, J., Elsaesser, B. & Windt, C. Paper presented at International Conference on Offshore Renewable Energy, Glasgow, United Kingdom, 2014.