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

* This paper was completed under the collaboration of the whole team. The specific contributions were as follows. The first author Donglin Zou developed the theoretical models and MATLAB codes, performed the analyses and wrote the manuscript. Fangrui Lv and Na Ta post-processed the data. They also compared the calculation results with the experimental results. The corresponding author Zhushi Rao made a critical revision.

ABSTRACT

Shafting 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.

KEYWORDS:

• Hydrodynamics
• propeller
• BEM
• bearing forces
• rotordynamics

Acknowledgement

This study was supported by a grant from the National Natural Science Foundation of China (No. 11802175) and China Postdoctoral Science Foundation (No. 2018M632107). The authors express their gratitude. The authors also thank Dr. Joao Manuel Baltazar from the University of Lisbon for providing with some experimental data.

Disclosure statement

No potential conflict of interest was reported by the authors.

Notes

* This paper was completed under the collaboration of the whole team. The specific contributions were as follows. The first author Donglin Zou developed the theoretical models and MATLAB codes, performed the analyses and wrote the manuscript. Fangrui Lv and Na Ta post-processed the data. They also compared the calculation results with the experimental results. The corresponding author Zhushi Rao made a critical revision.

Additional information

Funding

This study was supported by a grant from the National Natural Science Foundation of China [grant number 11802175] and China Postdoctoral Science Foundation [grant number 2018M632107]. The authors express their gratitude. The authors also thank Dr. Joao Manuel Baltazar from the University of Lisbon for providing with some experimental data.