High tidal current speed is likely to occur in the Belgian Part of the North Sea (BPNS). This problem affects both aspects of the marine operation analysis which are the local wave field near a monopile and the estimation of the allowable limit of the vessel. These two factors are important parameters to assess the safe or not-safe condition of marine operations. The two aspects are currently well predicted by most of the commercial hydrodynamics solvers that use linear potential flow assumption. However, the prediction neglects the existence of current and starts to deviate in high wave-height condition (i.e. nonlinear waves).

 

In this research, Computational Fluid Dynamics (CFD) solver is employed to account for the non-linearity of the waves and the effect of the current. The first part of the research compares the prediction of the wave field around a monopile with and without current between the linear potential flow and CFD calculation. The diffracted wave field is then utilized in the second part of the research to assess the vessel performance located near the monopile. In this way, based on the operation limit, the wave height threshold for the vessel can be derived. Crew transfer vessel are taken as the operational case in this study.

 

From this research, a general picture on the effect of current on both wave field around monopiles and vessel response can be given. Consequently, marine operation assessment can be done more accurately and executed more safely.