Hull Form Study for NYK-STX 2700 TEU Container Vessel - Technical Report C2600-13CT15-RAP01

Experiments have been carried out at CNR-INSEAN of a Container Vessel model equipped alternatively with three interchangeable bulbous bows: the original bulb-B1 and two alternative design named B2 and B3. The alternative bulbs showed very close performances between them, while both resulted in an effective power improvement in ballast condition, -25% to -6%, with respect to the bulb-B1. At the design load instead a -5% of gain was confirmed at the lowest speed, but in contrast with an increased PE at the highest speeds (+5%). The bulb-B1 configuration was tested in propulsion conditions to evaluate the effects of a Pre-Swirl Stator device (PSS). The tested PSS is a 5-bladed stator, mounted on the stern boss just upstream of the propeller for generating swirling flow to the propeller. Alternating results are obtained along the interval of speeds tested, with variations of the delivered power inside a range of ±1%. An assessment of the accuracy of the measurement was performed for the with-PSS configuration. The combined standard uncertainties uc result equal to 0.5% of the measurement for the torque, 0.1% for rate of revolutions 0.8% for thrust.