Coupled transverse and torsional vibrations of the marine propeller shaft with multiple impact factors

Abstract

An appropriate assessment of the dynamic behavior of a ship's marine propeller shaft is essential to enable the optional power delivery to the propeller and to minimize various vibrations during the rotation. As the mechanism of coupled transverse-torsional vibrations for the shaft is not fully revealed, which seriously affect the stability and reliability of ship's navigation. An accurate and applicable numerical model for the coupled vibrations of marine propeller shaft is thus proposed to solve this problem. This non-linear model with ordinary differential equations is analytical calculated on the basis of high order Runge-Kutta method. Experiments are conducted to validate the applicability of the proposed model through the comparison with numerical calculation, over a range of rotational speeds. The impact factors including eccentricity of cross section, damping coefficient and length-diameter ratio are discussed by comparing the Poincare surface of section. And the influence on the transient accelerations of the coupled vibrations are investigated in detail. The optimized design for marine propeller shaft is thus realized based on the adjustment of the unbalance quantity and structural dimension.