Whirling Vibration Modeling for Propulsion Shafting

As the transmission device of the ship, the vibration of the propulsion shafting has a very important influence on the overall working performance of the ship. Based on the transfer matrix method, the lumped parameters-distributed parameter hybrid model of propulsion shafting's whirling vibration is established in this paper. The simulation result shows that the model can reflect the system dynamics well. On the basis of the whirling vibration model, the influence of the rear stern bearing's supporting position and the propeller's entrained water effect are analyzed. Moreover, the natural frequency of the propulsion shafting increases with the increase of the rear stern bearing's equivalent stiffness. The propulsion shafting's variation law of the natural frequency with the above characteristics is revealed.