The Effect of the Shaft Diameter and Torsional Stiffness on the Whirling Speed of the Ship Propeller Shafting System

Abstract

Finding the whirling speed of the shaft of the ship propeller is presented on this paper. Power generated from the engine is transmitted to the propeller directly/indirectly using gearbox. This is important to find the natural frequencies of the shafting system in order to prevent resonance. So, multi-DOF (degree of freedom) is considered on this study including engine, gearbox and propeller, flywheel and etc. connecting by the shaft. Whiling speeds of the shaft are determined at various conditions as well as the effect of the shaft torsional stiffness and shaft diameter are presented and discussed.