Influence of Surface Waves—Von Karman Street Interaction on Bottom Sediments Transport in the Vicinity of a Wind Turbine Mast: Experimental and Theoretical Study

Cylindrical structures used in offshore energy production systems are subjected to various stresses and loads (waves and currents). Understanding the interactions between these cylindrical structures and bedforms is critical, as rapid changes in the bathymetry can expose and damage pile foundations and cables. The impact of a vertical cylinder on a sandy sedimentary bottom subjected to hydrodynamic currents and surface waves is experimentally and theoretically studied. Tests were carried out at the wave flume where patterns are produced. It is observed that patterns emerge due to a subcritical instability at the water-sand interface at the bottom. The characteristics of these patterns can be explained using the Swift-Hohenberg equation. Finally, the experimental results will be applied to the numerical model using the Swift-Hohenberg equation.