Open AccessCalculation of the Dynamic Characteristics of Ship’s Aft Stern Tube Bearing Considering Journal Deflection
Author(s) -
Hongjun Yang,
Jun Li,
Xiaolong Li
Publication year - 2020
Publication title -
polish maritime research
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.374
H-Index - 21
eISSN - 2083-7429
pISSN - 1233-2585
DOI - 10.2478/pomr-2020-0011
Subject(s) - stern , bearing (navigation) , deflection (physics) , reynolds equation , stiffness , structural engineering , vibration , mechanics , engineering , computer science , reynolds number , physics , classical mechanics , marine engineering , acoustics , turbulence , artificial intelligence
Dynamic properties are vital for the working reliability of aft stern tube bearings. However, the determination of such properties currently involves several simplifications and assumptions. To obtain its dynamic characteristics accurately, the aft stern tube bearing was divided into several bearing segments. The oil film reaction force was considered in the calculation of shaft alignment, and the journal deflection and actual oil film thickness were obtained accordingly. Subsequently, the perturbed Reynolds equation was solved using the finite difference method when the dynamic characteristics of journal bearings with finite width were evaluated. Then, a calculation program was developed and verified by comparing with the results of other studies. Finally, the dynamic characteristics were calculated under different revolutions. The results showed that the stiffness at the vertical direction of the aft stern tube bearing was several times that of the horizontal direction and varied with the revolutions of the shafting system. These findings can provide the foundation for the precise calculation of the journal trajectory under dynamic conditions, as well as for the evaluation of the oil film thickness. Moreover, the results led to favorable conditions for the accurate calculation of the shafting whirling vibration.