Thruster is the core equipment of ship navigation, and the choice of thruster is the core factor affecting the combat effectiveness of ship. The state-of-the-art of typical thrusters has been outlined based on the development of the equipment and technology of high-performance ships. It focuses on the relationship between the propulsion system and the ship hull with a systematic analysis from two aspects: the influence of requirements of ship multiple operation conditions, high speed and low noise on the development of the propulsion technology, and the improvement of the performance of ships by the development of propulsion technologies such as special propeller propulsion and waterjet propulsion. The effects of using propellers and waterjets on the resistance, maneuverability and noise of the ship are compared based on the full-scale and model test data of a 600 t law enforcement platform and a Swedish Navy Vessel. Combined with the state-of-the-art of high-performance ships in China, the development of the thruster technology is finally prospected to meet the requirements for the overall performance improvement of ships.

The computational fluid dynamics (CFD) method has been adopted to optimize the twin-skeg hull line of the twin-skeg Ro-Ro ship from the wake uniformity and the resistance in view of the technical problem that it is difficult to optimize the stern line of the twin-skeg ships. The wake objective function and the average wake fraction proposed by MARIN are used as the evaluation criterion for the wake uniformity. It analyzes the effects of the angle of run of the skeg at 0.8 R above the stern shaft, the fillet radius for the skeg, and the distance between the propeller disk and the stern shaft outlet on the wake uniformity and the resistance. The results show that with the basically constant ship form parameters, the variation of the skeg characteristic parameters will cause the change of the wake uniformity, average wake fraction and resistance. The twin-skeg hull lines are also optimized by the comparative analysis.