Research and Application on Mathematical Model of Ship Manoeuvring Motion under Shallow water effect

Abstract

When ships sail on the inland river in mountainous areas, the limited water depth can frequently lead to shallow water effect. To some extent, safety and maneuverability of shipping will be impacted. Consequently, it's necessary to consider the shallow water effect when studying the ship ascending rapids in mountainous rivers. By considering the impact of shallow water effect, a three freedoms maneuvering mathematical model based on shallow water effect was established in this paper on the basis of two-dimensional water flow mathematical model. Application of the model was implemented on the regulation of the waterway in Suoluo rapids section of the Lancang River to obtain ship navigating parameters (helm angle, drift angle, heading angle, ship's speed and speed against the water) for comparative analysis. Results show that the ship can reduce the impact of shallow water effect by adjusting the rudder angle and reducing the ship speed when navigating in shallow and narrow channel. The obtainment of the voyage line diagram by the simulation of ship's maneuverability test validates that the ship can ascending rapids through self-propulsion after the river regulation.