Comparison of hydrodynamic characteristics on two ship propulsors (PRS and AZIPOD)

This paper presents a comparison of the hydrodynamic characteristics of two ship propulsors, a conventional system that is a propeller-rudder system (PRS), and another which is the azimuthing podded drive system (AZIPOD). In order to calculate the performance characteristics of PRS and AZIPOD, which are lifting surface bodies, the propeller vortex theory is applied to calculate the forces acting on the propeller, assuming an infinitely bladed propeller. The panel method in the lifting body theory is adopted to calculate the forces acting on the rudder and steering system. Computed velocity components show good agreement with experimental measurements behind a propeller both with and without a rudder. Calculated thrust, torque and lift also show good agreement with the experiments. Computations are also given for an AZIPOD. Although our insight show that the numerical results of the hydrodynamic performance for the AZIPOD system are qualitatively good, it is recommended that it be examined with the experimental data.