Francois Flocard

BE, MES
Postgraduate Research Student
Environmental Fluids Group




School of Civil Engineering, Room 101
Phone: +61 2 9351 4393
Fax: +61 2 9351 3343
Email:

Research project - Ocean wave energy conversion by vertical cylinders subjected to irregular waves

Supervisor: Prof Kim Rasmussen
Associate Supervisor: Dr Tim Finnigan

Point absorbers are currently one of the main categories of wave energy converters being developed worldwide. These devices are classified by their dominant mode of motion relative to the water surface, that is heaving, surging or pitching. Most of these converters use either a hydraulic system or direct drive electric generator as a means for power take-off (P.T.O.). These wave energy devices are highly suitable for intermediate depth offshore locations.

The aim of my research is to study the power capture of bottom pivoted pitching cylinders in intermediate water depth subjected to regular and irregular waves.

The geometry of the pivoted cylinder, external damping and additional inertia (to simulate the impact of water ballasting) were taken as variable parameters in order to optimize the power capture efficiency in different wave conditions.

Wave tank simulation of EMEC (European Marine Energy Center) measured wave climate enabled us to obtain an understanding of the true hydrodynamic behavior and a reliable estimation of the possible power output from devices in operation.

My research investigates the respective influence of critical parameters such as geometry, damping and ballasting of wave energy converters in order to maximize their efficiency in real sea states.

By employing canonical shapes such as vertical cylinders, as opposed to specific designs, the aim of this study is to reveal their fundamental behaviour, which may then assist the development of more complex and efficient devices.

The tests are carried in the 30m wave tank facility at the School of Civil Engineering, capable of producing complex irregular waves that simulate ocean wave conditions in order to develop a better understanding of behaviour near resonance, develop ways to maximise energy absorption under realistic wave conditions.

Pitching rig in the wave flume

Some of the different shapes tested

Selected publications

• Flocard, F., Frandsen, J.B., Finnigan, T.D., 2008, Experimental investigation of power capture from pitching vertical cylinders in irregular waves, Proceedings of The 2nd International Conference on Ocean Energy, Brest, France.

Learning & Teaching

• CIVL2611 Fluid Mechanics
• CIVL2201 Structural Mechanics