CFD investigation into the effect of GM variations on ship manoeuvring characteristics

Abstract

The change in a ship's loading condition may induce a displacement of its vertical centre of gravity, subsequently impacting the metacentric height (GM) of the vessel. Such alterations can have unforeseen effects on the ship's manoeuvring behaviour. This study investigates these effects by developing a free running manoeuvre model for the KRISO Containership (KCS) based on the Unsteady Reynolds-Averaged Navier-Stokes (URANS) method. A multi-level dynamic overset grid and the body-force propeller method were employed to simulate the ship motion involving rudder manipulations. The numerical calculations of zigzag and turning manoeuvre revealed that the variations in GM produce significant alternations in the roll motion during manoeuvres, consequently affecting the zigzag and turning trajectories of the vessel.