SCOUR MECHANISM INDUCED BY PROPELLER FLOW NEAR A QUAY WALL
AbstractIncreasing ship dimensions in recent years cause structural instability due to the scouring problem during berthing and unberthing maneuver of the vessels. The propeller jet has 3D flow area and high velocities that may cause erosion problem around the berthing structures in three ways. These are; a) On a slope, b) At the toe of vertical wall, c) Around piles. In general scour problems are investigated by using physical modeling. Propeller jet induced the scour in front of the wall has been well studied in the past (Hamill et al. (1999), Ryan et al. (2013(a)), Ryan et al. (2013(b))). In this study, propeller jet flow was considered to investigate the seabed scour mechanism with and without vertical quay wall conditions and their comparisons were made. Three different distances of the propeller from the wall at Xw=0.7 m, 0.35 m and 0.175 m were tested for different clearances at G=0.1 m and 0.15 m on sand bed of d50=0.052 mm to give an extensive definition for scour depth estimation.
Hamill, G. A., Johnston, H., and Stewart, D. (1999): Propeller wash scour near quay walls.â€ J. Waterway, Port, Coastal, Ocean Eng., 10.1061/(ASCE)0733-950X(1999)125:4(170), 170-175.
Ryan, D., Eng, C., Hamill, G.A., (2013 (a)): Determining Propeller Erosion at the Stern of a Berthing Ship, Journal of Waterway, Port, Coastal, and Ocean Eng, 139 (4): 247-255.
Ryan, D., Hamill, G.A., Johnston, H.T. (2013(b)): Determining Propeller induced Erosion alongside Quay Walls in Harbours using Artificial Neural Networks, Ocean Engineering, 59 142-151.