MEASUREMENTS AND ANALYSIS OF FLUCTUATING PRESSURE INDUCED BY A PROPELLER, 2ND REPORT - CONTAINER SHIP

The first report dealt with the propeller-induced pressure fluctuation of fully loaded broad ships. This second report discusses the pressure fluctuation of two containerships in ballast condition. The theoretical calculation frequently gave a higher level of pressure-fluctuation than that which was measured, using a highly cavitating propeller. This did not, however, apply when a ship had a blunt waterline-end at the upper-fore part of the propeller, in which case the measured level of the twin blade frequency component was very high. The phenomena involved are discussed and it is concluded that although the accuracy of the theoretical calculation presented is not particularly good it is nevertheless useful in design work, if taken as a single parameter in the evaluation of propeller excitation.