In this second report the optimization of rudders is studied from resistance and propulsion point of views, where a synthetic, rather than analytic, method of approach is applied in contrast with the first report.
Based upon Kumano's (1960-61) finding that the ship's rudder occupies near optimum position as stern bulb which is aimed at stern wave cancellation, several types of unconventional rudder configuration are examined both by towing test and by wave analysis. Possible improvement of self-propulsion factors is also pursued by propulsion test.
Obtained increment of propulsive performance reaches up to 7 percent, which is mainly attributable to stern wave cancellation.
Viscous scale effects upon the main hull stern wave system both in towing and self-propulsion condition are studied by two geosim models of L=2.5m and 10m.