Development of Marine Propellers with New Blade Sections for Container Ships

A propeller design method using the newly developed blade section (KH18), which behaves better cavitation performance, is presented. Two-dimensional characteristics of the new blade section are compared with those of widely used NACA sections and the Eppler sections which were designed with prescribed pressure distributions along the foil surface. Experimental results for two-dimensional foil sections show that the lift-drag curve and the cavitation-free bucket diagram are wider compared to those of the existing foil sections. A lifting surface theory is used for the design of propellers with the developed section for a 2700TEU container ship. Since the most suitable chordwise loading shape is not known a priori, three types of loading shapes are selected from the two-dimensional analysis of the KH18 section. To investigate the influence of the chordwise loading shapes on the propeller performances, three propellers with different chordwise loading shapes were designed. Model test results show that the propeller using the KH18 section with less loading near the leading edge at the inner radii of 0. 7 radius and more loading near the leading edge at the outer radii has higher propulsive efficiency and better cavitation performance than the conventional propeller for this container ship application. Full-scale sea trial results with the selected propeller are also presented.