Sediment movement induced by ships in restricted waterways.

A numerical model using the momentum theory of propeller and Shields' diagram was developed to study sediment movement induced by a ship's propellor in a restricted waterway. The velocity distribution downstream of the propeller was simulated by the Gaussian normal distribution function. The shear velocity and shear stress were obtained using Sternberg's formulas. Once the ship's speed, depth of the waterway, RPM and diameter of the propeller, and draft of the ship are given, the velocity distribution and the grain size of the initial motion could be obtained from this model. A computer program was developed to solve it. Case studies are presented to show the influence of significant factors on sediment movement at the channel bottom induced by a ship's propeller.