CFD and system-based investigation on the turning maneuver of a twin-screw ship considering hull-engine-propeller interaction

Abstract

Ship maneuver is a dynamic process accompanied by strong interaction among hull, engine, and propeller, and the interaction phenomenon is more complicated for twin-screw ships. In this paper, numerical investigation on the turning maneuver of a twin-screw ship considering hull-engine-propeller interaction is carried out by using CFD and system-based methods. Taking the twin-screw ship ONRT model as the study object, a series of captive model tests are simulated by using RANS method. Based on the computed global loads on the propellers and the corresponding flow field details, the hydrodynamic characteristics of the propellers operating under the maneuvering conditions are analyzed. The effective wake fraction is computed and the mathematical model of propeller performance under the maneuvering conditions is obtained through data fitting. Based on the established mathematical model, the turning circle maneuver considering hull-engine-propeller interaction is simulated. Three control strategies of main engine, i.e., constant RPM, constant torque, and constant power, are considered. The effects of the control strategies on the turning motion and the propulsive loads during turning motion are explored. This study is useful to provide a deeper insight into the ship maneuvering behaviors and the propeller characteristics during maneuvering motion under the influence of hull-engine-propeller interaction.