Local scour around the monopile based on the CFD-DEM method: Experimental and numerical study.

In the offshore environment, monopile foundations are facing significant local scour problems, which would have a serious negative impact on their stability and safety. The numerical simulation provides us with an efficient tool to investigate the patterns and underlying mechanisms of local scour. In this study, an Euler-Lagrange two-phase flow (CFD-DEM) model was employed to simulate local scour around monopiles. The CFD-DEM model was utilized to simulate several different scenarios, including sediment transport under undisturbed flow, flow around monopiles, and local scour around monopiles. In the first scenario, the LES model was incorporated to simulate turbulent flow, and it was observed that the CFD-LES-DEM model accurately predicted flow characteristics and sediment behavior within the water–sediment two-phase system. In the second scenario, the flow around the monopile was simulated under rigid bad conditions, and the characteristics of the flow field, including the horseshoe vortex and the wake vortex, were studied and validated. In the last scenario, the local scour around monopiles was simulated under different mean flow velocities, with simulation results being validated through model experiments. Based on experimental and numerical results, the phenomena and mechanisms of local scour were studied from a particle-scale perspective. [ABSTRACT FROM AUTHOR]