Research on the waterjet attainable thrust region of steering and reversing in self-propulsion

Accurate attainable thrust region of waterjet system is one of the key techniques for developing ship maneuvering strategies, significantly impacting the success of vector control and dynamic positioning technologies. During the ship maneuvering, the hull drift angle affects the intake condition and then influences the waterjet thrust performance, altering both the range and the shape of the attainable thrust region. Based on a typical dual-waterjet propelled mono-hull, this paper numerically investigates the steering and reversing attainable thrust region under various drift angle conditions, where the variations of the attainable thrust region with the drift angle are obtained and the hydro-mechanism is analyzed. The results indicate that the drift angle induces a movement and a slight shape change of the attainable thrust region, and the force exerted by the intake flow on the duct is the main reason for these variations. Furthermore, the attainable thrust region under a given drift angle is functionalized as a formula for fast retrieval in the database of waterjet thrusts. The research can provide technical support for hydrodynamic modeling in vector control and dynamic positioning studies.