Channel width effects on berthed ship - passing ship interaction from experiments and CFD predictions

To date, most investigations into berthed ship - passing ship interactions have assumed that the berthed ship is in relatively open water, albeit at low water depth to draught values, with only a few cases reported where the presence of the wharf or near bank (alongside the berthed ship) is considered. This is despite the fact that in most realistic cases there is the presence of a bank, or other structure, alongside the berthed ship. This paper presents results from a series of physical scale model experiments on berthed ship - passing ship interaction for cases in a rectangular channel. Two channels widths were tested, one to represent wide channel, where the effects of the lateral banks are negligible, and one to represent a narrow channel, where the effect of the lateral banks are significant. The physical scale model experiments were also used to validate preliminary CFD predictions using an inviscid double body model to determine the ability of the CFD model to predict the interaction forces and moments in the wide and narrow channels. The interaction forces and moments from the experimental and CFD results were scaled to represent full scale vessels and used as input to a numerical simulation software package to predict the motions and mooring loads experienced by the berthed ship due to a passing ship for a selected mooring arrangement. The results demonstrate that a narrow channel can significantly influence the interaction forces and moments and hence can considerably modify the predicted motion and mooring loads on the berthed ship. It is shown that the influence of site-specific blockage around berthed ships due to the near bank should be accounted for in order to accurately predict the influence of a passing ship on a berthed ship when designing a port to ensure safe and efficient operations.