This thesis investigates a passive exchange system of the enclosed water inside a monopile, with the sea water . This increases the pH-value of the water inside and decrease the corrosion of the anodes.
The exchange system is investigated through numerical CFD simulation of the flow inside the monopile, in both two- and threedimensional models. The exchange is through one or more holes drilled in the monopile.
The models are simplified by a comparison between the simulation and the energy equation. The internal flow is validated through laboratory experiments, which are compared with simulated CFD models.
It is found that hardly no exchange occurred from current, but a complete exchange might be possible from both tides and waves. The most promising results are from the wave conditions, as this introduce a higher velocity in the flow thought the holes.
The results of this thesis suggest that a exchange system, such as this, could result in a reduction of up to 80 % of the anode material needed for the corrosion.