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A study of the analysis of shaft alignment considering hull deflections for 50,000 DWT oil/chemical tankers

5만 DWT 석유화학제품운반선의 선체변형을 고려한 추진축계 정렬해석 연구

  • Received : 2016.02.05
  • Accepted : 2016.03.14
  • Published : 2016.03.31

Abstract

The shaft system of a vessel becomes stiffer because of larger engine power, whereas the hull structure becomes more flexible because of scantling optimization conducted by using high-tensile thick steel plates. The draught-dependent deformation of the hull affects each bearing offset and reaction force comprising the subsequent shaft system. This is the reason that more sophisticated shaft alignments are required. In this study, an FE analysis performed under the expected operating conditions of two (2) vessels, as maximum draught change and to analyze the shaft alignment using the relative bearing offset change, which was derived from an FE analysis of the 50,000 DWT oil/chemical tanker, which has become an eco-friendly vessel in recent years. Based on this, the influence of the hull deflection on the bearing offset was reviewed against results for shaft alignment conditions.

선박이 고출력화, 대형화 됨에 따라 추진축의 강성은 증가한 반면에 선체는 고장력 후판을 사용하므로 이전의 선체보다 훨씬 더 쉽게 변형되는 실정이다. 흘수변화에 따른 선체변형은 축계를 구성하는 각각의 베어링 옵셋 및 반력에 연쇄적인 영향을 미치게 된다. 이는 기존의 선박보다 더욱 정교한 축계정렬이 요구됨을 의미한다. 본 연구에서는 최근 친환경 고효율 선박으로 등장한 5만 DWT급 석유화학제품운반선을 대상으로 선박의 흘수 변화에 따른 선미부 구조해석을 실시하고 구조해석으로부터 얻어진 축계의 상대변위를 이용하여 축계정렬 해석을 수행하였다. 구조해석은 선박의 통상 운항조건에서 최대 흘수 변화를 고려한 2개 조건에서 수행하였다. 이를 바탕으로 선체변형에 따른 베어링 옵셋 변화가 축계정렬에 미치는 영향을 검토하였다.

Keywords

References

  1. R. Michel, "A quarter century of propulsion shafting design practice and operating experience in the U.S. navy," Journal of the American Society for Naval Engineers, vol. 71, no. 1, pp. 153-164, 1959.
  2. H. C. Anderson and J. J. Zrodowski, "Co-ordinated alignment of line shaft, propulsion gear, and turbines," Annual meeting of the Society of Naval Architects and Marine Engineers, pp. 449-523, 1959. [Online]. available: http://www.sname. org/HigherLogic/System/DownloadDocumentFile.ash x?DocumentFileKey=51feb692-25ae-4b8b-bf4f-55bdea11ed48
  3. W. E. Lehr "Considerations in the design of marine propulsion shaft system," Society of Naval Architects and Marine Engineers, vol. 67, p. 555, 1961.
  4. G. Mann, "Shipyard Alignment of Propulsion Shafting Using Fair Curve Alignment Theory," The American Society of Naval Engineers Journal, vol. 77, no.1, pp. 117-133, 1965. https://doi.org/10.1111/j.1559-3584.1965.tb05656.x
  5. American Bureau of Shipping (ABS), Guidance Notes on Propulsion Shafting Alignment, Houston, USA : American Bureau of Shipping : ABS, 2006.
  6. K. C. Kim and J. G. Kim, "A study on optimum shaft alignment analysis for VLCC," Proceedings of the special transactions of the Society of Naval Architects of Korea, pp. 134-137, 2005 (in Korean).
  7. H. J. Jeon, Ship Propulsion Transmission Equipment, Busna, Korea, Taehwa Publishing Company, 1986 (in Korean)
  8. C. O. Seo, A Study on the Optimal Shafting Alignment for Chemical Tanker of Medium Size, M.S. Thesis, Department of Marine System Engineering Graduate School, Korea Maritime University, Korea, 2010 (in Korean).
  9. J. U. Lee, A study on the Optimal Shafting Alignment Concerning Bearing Stiffness for Extra Large Container Carrier, M.S. Thesis, Department of Marine System Engineering Graduate School, Korea Maritime University, Korea, 2011 (in Korean).
  10. L. Shi, D. Xue, and X. Song, "Research on shafting alignment considering ship hull deformations," Marine Structures, vol. 23, no. 1, pp. 103-114, 2010. https://doi.org/10.1016/j.marstruc.2010.01.003
  11. J. M. Jung, I. H. Choe, and S. H. Shin, "A study on elastic shaft alignment using nonlinear bearing elements," Journal of the Society of Naval Architects of Korea, vol. 42, no. 3, pp. 259-267, 2005 (in Korean). https://doi.org/10.3744/SNAK.2005.42.3.259
  12. MAN B&W, "Bearing load measurement by jaking up", ID No. 07424-5, 2012.
  13. KR, Rules for the Classification of Steel Ships Part 5 Chaper 3 206, Busan, Korea, Korean Register, 2015.
  14. Class NK, GUIDELINES ON SHAFTING ALIGNMENT, Japan, Class NK, 2006.
  15. Korean Register of Shipping, SeaTrust-Machinery User Manual ver.1.0, Busan, Korea, 2013 (in Korean).

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