Characteristics of Propeller-induced Flow and Scour around a Vertical Quay Wall

During the berthing and deberthing process, the quay structure is often present in close proximity to the ship propeller and the resulting local scour hole around the base of the quay wall is a growing concern as it may result in structural instability or even failure. The aim of this study is to investigate the characteristics of the propeller induced flow field and its associated scour hole around a vertical quay wall. In order to examine the concurrent developments of the scour hole and the flow field in and around it, an “oblique particle image velocimetry (OPIV)” technique was employed in measuring the streamwise flow field (jet central plane) and the longitudinal centerline scour profile. The results show that the jet diffusion and the associated energy dissipation is significantly altered by the presence of a vertical wall. The characteristics of the mean flow pattern within the developing scour hole are discussed in this paper. Furthermore, the difference in scouring mechanisms associated with the close quay (with a vertical quay wall) and the open quay (with a slope) is examined in terms of the vortex evolution.Finally, a comparison of the near-bed flow characteristics of the average kinetic energy (AKE), turbulent kinetic energy (TKE), and Reynolds shear stress (RSS) are also discussed in terms of their implications to the scour hole development.