Preliminary Development of a Pseudo-3D Testing Technique for the Prediction of Extreme Loads on an Oscillating Wave Surge Converter

If wave energy is to become a sustainable and economic
power source it is essential that extreme loading mechanisms
experienced by Wave Energy Converters are well understood.
Previous work completed at Queen’s University Belfast in
collaboration with Aquamarine Power Ltd. highlighted slamming
as an extreme loading mechanism experienced by pitching flap
type devices. Testing has previously been undertaken in both 2-
and 3-dimensional environments. This paper undertakes
qualitative and quantitative comparisons of extreme loading
investigations undertaken within those two environments. The
results show that the hydrodynamics and magnitudes of slams
experienced by the device in a 2-dimensional environment vary
significantly from those experienced in the more realistic 3-
dimensional environment. It is therefore undesirable to utilise 2-
dimensional testing for extreme load quantification. It is also
noted that visual inspection of the event (which has proven to be
essential in identifying the hydrodynamics of many load
characteristics observed) is significantly more difficult during 3-
dimensional testing. As a result of the findings, ongoing research
at Queen’s University Belfast seeks to develop a new testing
methodology in an attempt to realize the benefits of both the 2- and
3-dimensional experimental setups from a single experimental
setup. The technique has been termed Pseudo-3-dimensional, or
2½D testing. Preliminary results obtained from early tests
undertaken are presented in this paper.