Estimating manoeuvring coefficients of a container ship in shallow water using CFD

The International Maritime Organization (IMO) has been keen in dealing with aspects of ship maneuverability, which are vital to its objectives of safer shipping and cleaner oceans for the past three decades. The standards specified by IMO on ship manoeuvring are for deep water condition, whereas it becomes more demanding on the designer to come up with a vessel which meets the more stringent requirements of controllability in shallow and confined waterways. The dynamic tests performed on a ship model using PMM in a towing tank yield these hydrodynamic coefficients, both linear and non-linear components in uncoupled and coupled modes of sway and yaw. The objective of the present work is to study shallow water effect on the manoeuvring coefficients of a container ship (S 175) model in a numerical towing tank. In dynamic simulations, the prescribed body motions have been imposed on the hull using user-defined field functions within the commercial CFD solver in pure sway and pure yaw mode. The hydrodynamic derivatives have been derived for the shallow water depths and are found to be in reasonably good agreement with the experimental data.