0pen-Water Characteristics and Load Fluctuations of Propeller in Waves

Abstract

In order to investigate the propeller characteristics in waves, open-water tests at the conditions of forced heave, pitch and surge oscillations in still water as well as in regular and irregular waves are carried out with a five bladed 15 cm diameter propeller. The mean values of fluctuation of the measured thrust and torque are compared with the open-water characteristics in uniform flow. Furthermore, self-propulsion tests in regular and irregular waves are carried out with a ship model of single screw high speed container ship, and propeller load fluctuations are measured. The measured amplitudes of propeller load fluctuation in open-water tests and self-propulsion tests are compared with the theoretical calculations by using the propeller open-water characteristics in uniform flow or the Sears' unsteady airfoil theory.