Research on Dynamic Characteristic of Marine Shafting-Oil Film-Stern Structure System

Abstract

The working conditions of the propulsion system of ships are affected by many factors and partially by hull deformations and lubricating oil film. In order to solve the problem of engineering application of reliability assessment and control of ship propulsion system on heavy sea, a mechanical model of ship shafting-oil film-stern structure coupled system is established. The hull and shafting are studied as a whole, and a test rig with the wave loads system is assembled. By carrying out the integrative analysis and physical experiment, the motion characteristics of the system are analyzed. According to the various types of wave loads which ship faces on ocean, the influence of the stern structure on the vibration characteristics of the shafting is obtained. It is concluded that the coupling degree of shafting and stern structure is correlated with the natural frequency of the coupled system, and the wave-induced loads response is correlated with wave encountering frequency. The characteristics of the shafting-oil film-stern structure system, such as the maximum amplitude of tail shaft and the minimum oil film thickness of bearing, are significantly modified under the influence of stern structure.