Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE credits
This is a master thesis conducted during the autumn and winter 2010-2011 at KTH Centre for Naval Architecture in collaboration with Wallenius Marine AB.
Traditionally the hull lines of typical Pure Car and Truck Carriers have been optimized for minimum resistance when going on a straight path and for maximum cargo capacity. This has resulted in vessels with slender underwater body, very high vertical centre of gravity and large flares in the waterlines of the aft body to provide form stability. Dynamic behaviour, such as manoeuvrability, has not been in main focus while designing the hulls.
To create a tool for assessing the manoeuvrability, a model describing the motions in four degrees of freedom of a vessel have been developed. The equations of motion in surge, sway, yaw and roll are set up and solved numerically in Matlab. The code has been validated against available benchmark results and calibrated using trial data from a number of vessels from the Wallenius fleet. Good compliance to trial results is achieved for the initial part of a turn but some problems occur in the later part.
Both trials and simulations indicate on very good turning and yaw checking abilities among the investigated vessels but also a tendency of dynamic instability.
2011. , 49 p.