FORE AND AFT VIBRATION OF MAIN ENGINE AND SHIP VIBRATIONS DUE TO THE TORSIONAL VIBRATION OF 5-CYLINDER MAIN ENGINE

An analysis has been made of hitherto insufficiently noted interactions between propeller, shafting and engine vibrations that induce signficant propeller thrust fluctuation due to torsional vibration of shafting. The amplitude of shafting torsional vibration at the position of the propeller was found to be strongly influenced by whether or not the fundamental mode natural frequency of this shafting vibration is shifted toward the higher or lower side of the normal range of engine-excited frequencies. When the natural frequency is shifted upward from the exciting frequency range, the exciting force generated by the torsional vibration is of the same order as the thrust variation of the propeller bearing force, and the order of vibration is the same as that of the torsional vibration. Such exciting force could induce ship vibration. The analysis is validated by comparisons with measurements on actual ships. Based on the above finding, principles for devising measures to reduce ship vibration are proposed.

• Supplemental Notes:
  • International Cooperation on Marine Engineering Systems '84, Trieste, 25-28 Sept. 1984. (15 pp., 10 ref., 3 tab., 4 diag., 11 graphs)
• Authors:
  • Kumazaki, S
• Publication Date: 1984

Language

• English

Subject/Index Terms

• Subject Areas: Marine Transportation;

Filing Info

• Accession Number: 00688087
• Record Type: Publication
• Source Agency: British Maritime Technology
• Files: TRIS
• Created Date: Aug 14 1995 12:00AM