Study On Prediction For The Maneuverability Of A Sail-assisted Ship

The maneuvering characteristics of a sail-assisted ship are very important for its design. The purpose of this study is to investigate the maneuverability of a sail-assisted ship. Based on the force analysis of a sail-assisted bulk carrier, the mathematical model for ship maneuvering is established. Then, its maneuverability, including freely maneuverable range,turning ability, course alterating ability and course controllability, are investigated via Matlab/Simulink software, and the optimal sail strategies are presented. Several achievements of the thesis can be summarized as follows:1) Influence on the freely maneuverable range for sail installed Based on the optimized sail-rudder strategies, freely maneuverable range can be enlarged 10.7%; Several suggestions for antiwind ability improved are presented;2) Influence on the turning ability for sail installed Taken example for sail locating angle at -90°, influence on the turning circle in calm water can be neglected; Drift distance is enlarged under wind conditions,but to the tactical diameter and advance are not obvious; Taken example for true wind angle at 0°, when sail attack angle is 180°, drift distance of both longitudinal and lateral are smaller than the ship without sails;3) Influence on the course alterations for sail installed Based on the optimized sail-rudder strategies, initial turning ability and couse alterating/keeping ability are improved except the true wind angle is 20°and 120°;4)Influence on the course controllability for sail installed Based on the optimized sail-rudder strategies, the maximum sailing speed is enlarged about 7.3 %, together with the course controllability is improved.