Experimental Analysis of Single Propeller Scour Dynamics Near Vertical and Parallel Quay Walls

Ship propeller jet-induced scour while berthing and unberthing poses a significant threat to berth structure stability. With the increase in size and capacity of vessels, the propeller-generated flow interaction with seabed erosion is gaining significance for port facility management. The present investigation experimentally investigates single propeller jet-induced scour behavior around quay walls of various wall configurations. Flume experiments in the laboratory were conducted with the use of sand of median grain diameter d₅₀ = 1.2 mm, 10 cm diameter propellers, and Froude numbers of 4.71 and 6.23. The role of rotational speed of the propeller, gap (G) vertically, and the propeller-wall distance were studied under conditions of unconfined (no-wall) and confined (parallel and vertical wall) cases. The results show that for unconfined cases, deeper gaps decrease scour depth and greater rotational speed increases it. In confined cases, deeper separation between the wall and the propeller decreases scour depth, and wall orientation significantly influences the scour profile. These kinds of results enhance understanding of the mechanisms of sediment transport near quay walls and allow for the development of predictive models for estimating scour.