Study on bearing force of marine propeller induced by longitudinal vibration of propulsion-shafting

Abstract

ABSTRACTShafting vibration can also produce bearing forces. The purpose of this study is to investigate the characteristics of such bearing forces. First, a new propeller bearing force prediction model that can consider the arbitrarily complex vibrations of the propulsion-shafting is established and then is validated by some numerical and experiment examples. At last, based on this model, the axial bearing force induced by longitudinal vibration of propulsion-shafting is mainly studied. The research shows that the axial vibration only causes the axial and torsion bearing forces, and does not lead to the lateral or vertical bearing forces. The amplitudes of axial bearing force are proportional to the longitudinal vibration amplitudes of propulsion-shafting, and are also squared with the vibration frequencies. This means that the nonlinear effect of wake vortex is not obvious, and the bearing force can be equivalent to constant added mass and added damping forces.