CFD simulations of a passively controlled point absorber

Presenter Information

MInghao Wu, Chalmers University of Technology
Weizhi Wang, Chalmers University of Technology
Johannes Palm, Chalmers University of Technology
Claes Eskilsson, Chalmers University of Technology

Event Type

Event

Location

Sasakawa Auditorium

Start Date

25-1-2017 3:30 PM

End Date

25-1-2017 3:45 PM

Comments

Recently CorPower Ocean presented laboratory tests of a point absorber wave energy converter equipped with a novel technique for passive phase control (Hals Todalshaug et al, 2015). The technique, known as WaveSpring, widens the response bandwidth by a negative spring arrangement, and in the tank experiment an up to three-fold increase in delivered power as compared to pure linear damping was observed. As previously reported, for point absorbers close to resonance the use of standard radiation-diffraction models can become unreliable while CFD simulations accurately captures the nonlinear wave height dependent response (Yu and Li, 2015; Palm et al, 2016). Thus, in the present study a module representing the Wave Spring technology was implanted in the OpenFOAM framework and CFD simulations of the buoy were performed both with and without the Wave Spring module. Good agreement between simulated and experimental results was observed, and the WaveSpring behavior was well captured in the numerical simulation. The CFD model can be used for further tuning of the WaveSpring/bouy design as well as providing validation data for radiation-diffraction models.