Investigations of the Propeller/Pre-swirl Stator Interactions in Calm Water and in Waves

Abstract

In this paper, the self-propulsions of a container ship designed by CSBC (named as P-Hull) which has a pre-swirl stator like energy-saving device, Y-Fin, are simulated in both calm water and in waves. The propeller/pre-swirl stator interactions are then investigated. In this paper, two different approaches of computing the ship resistances in self-propulsion simulations are used. For the resistance approach I, ship hull forces in calm water are all computed by the viscous flow RANS method, and the ship motions and added resistance are computed by a strip theory method instead of directly using RANS method. For the resistance approach II, only viscous flow RANS method is used for the simulations. The body force method is used in the present methods, and it is defined as using computed propeller forces to represent the effects of propellers instead of using the real propeller geometries. The Navier-Stokes equation is then solved by introducing these forces as body force terms. In the presented paper, the propeller forces are computed by potential flow boundary element methods. By carrying out self-propulsion simulations with different resistance approaches and different body force methods, we can then investigate the propeller/Y-Fin interactions. Through the investigations, we can understand different effects to the propeller/Y-Fin interactions, thus can help us to improve designs of Y-Fin in the future. It can also assist us to improve the propeller design for a ship with Y-Fin.