The effect of the stern shape and propeller location on the propulsive efficiency of a blunt ship

A reliable powering prediction is of critical importance at the design stage of a ship and the evaluation of the hull/propeller interaction constitutes a fundamental part of the propulsion performance estimation. Whilst the hull form and propeller geometry directly affect the interaction characteristics, the axial distance between propeller and hull is also a critical factor. This paper investigates the effect of different propeller positions and stern shapes on the self-propulsion characteristics of Kriso Very Large Crude Carrier 2 (KVLCC2) tanker. Hydrodynamic performance of the reference propeller (KP458) was first examined in open-water conditions for validation purposes. Two different longitudinal positions of the propeller were considered in the self-propulsion cases. Section shifting method was used to generate two variations of the original stern form. The approach adopted was simply based on deforming the shape of the associated cross-sectional area curve. Negligible changes in the displacement and wetted surface area were basically aimed for the hull form modifications.