Numerical analysis of pre-swirl stators for ship propeller

In this paper, the pre-swirl stator (PSS) for the propeller of a container ship is numerically simulated and analyzed. The parameters of the pre-swirl stator (PSS) are stated, and two most important paremeters, namely the number of stators and the angle of attack are considered and analyzed. The stators are chosen in three number of blades (four, six, and eight blades) and at five angles of attack (10, 11.25, 12.5, 13.75, and 15 degrees). In addition, the position of the stators is important, which is determined according to the flow direction in the ship stern. After analyzing the stator simulation results, the three stators, which have favorable performance in terms of efficiency, were selected as reference stators. Then, the thrust and torque coefficients for all blades and one blade of the propeller, and pressure at one point on the propeller blade are examined. The results are indicated that the stator with eight blades and at the angle of attack of 10 degrees has a better performance in terms of changing the direction of propeller inflow and producing thrust and torque. Therefore, it is improved that the efficiency and delivered power by 3.46% and 4.05%, respectively. Moreover, the four blades stator with an attack angle of 10 degrees has improved the pressure fluctuations by 8.45% compared to the non-stator condition.