Optimal Revolution B-Series Propellers

Abstract

The open-water characteristics of 120 propeller models of the B_Series were tested at the Netherlands Ship Model Basin in Wageningen (NSMB) and were analyzed with multiple polynomial regression analysis. The derived polynomials express the thrust and torque coefficients and the open water propeller efficiency in terms of number of propeller blades, blade area ratio, pitch_diameter ratio and advance coefficient. The effect of Reynolds number and variation of blade thickness on the propeller characteristics have also been calculated at NSMB. The open water propeller characteristics for Reynolds number 2.0 x 106 were plotted in report number 237 versus the advance coefficient for the ranqes of number of blades, blade area ratio and pitch-diameter ratio recommended by NSMB. &&In this report one of the preliminary propeller desiqn problems is studied. Namely the problem of calculation of the optimal propeller RPM for given diameter and hull speed.