A NUMERICAL SIMULATION OF LOCAL SCOUR PROCESS DUE TO WAVES AROUND MONOPILE FOUNDATION USING REEF3D

Monopile foundations are commonly constructed for offshore wind turbines and installed at depths shallower than 30 m. However, preventing scouring and erosion around the pile foundation due to waves is critical, as this can cause instability of the foundations and supported structures. In this study, model and numerical tests were conducted to investigate wave-induced scour and erosion around a monopile foundation and clarify the fundamental mechanisms involved. Numerical tests were conducted and validated against physical model tests for a bare sea bed, and good reproducibility was obtained. When a monopile foundation was installed in both the numerical and physical tests, the flow velocity on the seabed in the offshore and inshore directions increased on the side of the foundation perpendicular to the direction of the wave motion. In the model test, scouring occurred at the same location, indicating that scouring may have been caused by the flow velocity; however, this scouring occurred locally, suggesting the need for a detailed analysis of the associated factors.