Fossil fuels have been fundamental to the evolution of humanity's technology and way of life for
the last two centuries. However, their use has two main disadvantages: (a) the climate change
produced by the release of carbon dioxide (CO2) during their combustion; and (b) their limited
reserves. In the last decades, society has tried to counter these problems by potentiating the use
of renewable energies instead of fossil fuels.
The Ocean Grazer (OG) is one of the many proposed projects to develop the renewable energy eld
further. Developed by the University of Groningen, the OG platform is expected to extract and
store multiple forms of renewable energy, of which wave energy is its primary source. The main
innovation provided by the OG is a novel Wave Energy Converter (WEC) technology denominated
MP2PTO, which aims to adapt to the di erent wave pro les so the maximum energy content can
always be extracted.
In the last years, one of the many research lines in the group has been the study of the wave energy
extraction process in an experimental setup called the wave tank, which contains a prototype of
the multi-piston PTO concept used in the OG-WEC. More precisely, in the last few months,
experimental measurements of the velocity of the particles within the tank have been carried
out using the Digital Particle Image Velocimetry (DPIV) technique, taking into account di erent
scenarios that allow investigating the in
uence of the prototype in the process of energy extraction.
In this work, the validation of these experimental measurements of the kinetic energy contained in
the OG group's wave tank experimental setup is approached by the use of a computational
uid
dynamics (CFD) simulation software developed by the University of Groningen called ComFLOW.
In a rst phase of the validation process, a time domain analysis of the simulation results is done.
In this analysis, the non-convergence of the simulation is detected. However, the results of the
simulations are compared to the experimental measurements leading to a qualitative coincidence
of the evolution of the content of energy along the tank but not quantitative.
In a second phase, the non-convergence of the simulation is studied by means of a frequency
domain analysis of the wave tank's water surface height. This study allows the detection of a
strong mesh-dependant wave re
ection in the simulation's wave tank, which is the reason behind
the non-convergence of the simulation.
Consequently, due to this non-convergence, no validation of the experimental measurements can
be fully con rmed even though the behaviour of the kinetic energy along the simulation tank is
very similar to the experimental measurements. Finally, further research paths are proposed in
the Conclusion Section.
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