Improvement of Propulsive Efficiency by Dedicated Stern Thruster Design

The operation of a propeller in the vicinity of volumetric displacement bodies is characterised by strong interaction. In the design process of the propeller the local inflow velocity at the blade under consideration of the interference effects should be considered to prevent separation on the propeller blade. In case of a stern thruster the propeller is operating in the viscous wake and therefore a significant reduction in propulsive power is achievable if the propeller is adapted adequately to the reduced axial flow velocity. The present paper shows the potential of increasing propeller as well as propulsive efficiency by dedicated stern thruster design. To show the effects of tail shape two different hull shapes are examined. The influence of propeller diameter on the performance of the configuration is shown by three different propeller variants which were optimized in regard to the local axial inflow velocity.