Journal of the Korean Society of Marine Environment & Safety (해양환경안전학회지)

The Korean Society of Marine Environment and safety (해양환경안전학회)
권호 표지
DOI QR코드

DOI QR Code

Experimental Study on the Analysis and Estimation of Metacentric Height in Response to Roll Period and Moment of Inertia Variations in Ships

선박의 횡요주기와 관성모멘트 변화에 따른 GM 추정 및 분석을 위한 실험 연구

  • LeeChan Choi (Design Engineering Support Center, Research Institute of Medium & Small Shipbuilding) ;
  • JungHwi Kim (Design Engineering Support Center, Research Institute of Medium & Small Shipbuilding) ;
  • DongHyup Youn (Design Engineering Support Center, Research Institute of Medium & Small Shipbuilding)
  • 최이찬 (중소조선연구원 설계엔지니어링지원센터) ;
  • 김정휘 (중소조선연구원 설계엔지니어링지원센터) ;
  • 윤동협 (중소조선연구원 설계엔지니어링지원센터)
  • Received : 2023.05.12
  • Accepted : 2023.06.27
  • Published : 2023.06.30
Download PDF
⟨ Previous Next ⟩

Abstract

This study estimates the metacentric height (GM) of a model ship by varying the transverse weight distribution, considering the effects of the roll period and moment of inertia, and compares it with the GM values measured by the inclining test. In the process, the relationship between the values is analyzed. Three types of ships-a 7-ton fishing vessel, 20-ton fishing vessel, and KRISO Very Large Crude-oil Carrier (KVLCC)-were used for the experiment and comparison. The roll period and moment of inertia were measured using the free roll decay and swing frame tests, and the GM was measured using inclining test. The estimated GM from the roll period and moment of inertia showed the same trend as the GM measured using the inclining test in the change of the weight distribution. However, the GM values measured using the inclining test were lower. Therefore, additional correction factors or parameters other than the roll period and moment of inertia are necessary for estimating GM. In the future, the relationship between the weight center and the estimated GM will be analyzed to derive the correction factors.

본 연구는 모형선박의 횡방향 무게분포를 변화시키면서 횡요주기 및 관성모멘트에 의한 GM을 추정하고 경사시험으로 계측되는 GM 값과 비교한다. 그 과정에서 각 수치를 분석하여 관계성을 파악한다. 실험 및 비교에 사용된 선박의 종류는 3종류로 7톤급, 20톤급 어선과 KVLCC의 모형선을 사용하였다. 실험은 스윙프레임 테스트와 자유 횡요 감쇠테스트를 수행하여 관성모멘트와 횡요주기를 계측하고, 경사시험으로 GM을 계측하였다. 관성모멘트와 횡요주기로 추정된 GM과 경사시험으로 구해진 GM은 선박의 무게 분포 변화에도 동일한 경향을 보였지만, 경사시험에서 구해진 GM이 더 작은 값을 보였다. 따라서 GM 추정 시에 관성모멘트나 횡요주기 외에도 추가적인 보정 계수나 파라미터가 필요하다고 판단된다. 추후 무게중심을 변화시켜 추정 GM과의 관계를 분석하여 보정 계수를 산출할 계획이다.

Keywords

Acknowledgement

This research was supported by a grant (20015029) of Regional Customized Disaster-Safety R&D Program, funded by Ministry of Interior and Safety (MOIS, Korea).

References

  1. Choi, S. M.(2015), A General Formula for Calculating the Value of Transverse Moment of Inertia by Observing the Roll Motion of Ships. Journal of The Korean Society of Marine Environment & Safety, 21(5), pp. 538-542. https://doi.org/10.7837/kosomes.2015.21.5.538
  2. Delefortrie, G., S. Geerts, P. Peeters, and F. Mostaert(2017), Ship model calibration: determination of a ship model's moment of inertia. FHR reports.
  3. Gabl, R., T. Davey, E. Nixon, and D. M. Ingram(2021), Accuracy Analysis of the Measurement of Centre of Gravity and Moment of Inertia with a Swing, Applied Sciences, 11(12), 5345.
  4. Haddara, M. R. and P. Bennett(1989), A study of the angle dependence of roll damping moment, Ocean Engineering, 16(4), 411-427. https://doi.org/10.1016/0029-8018(89)90016-4
  5. Igbadumhe, J. F., O. Sallam, M. Furth, and R. Feng(2020), Experimental determination of non-linear roll damping of an FPSO pure roll coupled with liquid sloshing in two-row tanks. Journal of Marine Science and Engineering, 8(8), 582.
  6. IMO Resolution A.749(1993), Code on Intact for all Type of Ships Covered by IMO instruments.
  7. International Maritime Organization(2002), Code on Intact Stability for All Types of Ships Covered by IMO Instruments: Resolution A. 749 (18) as Amended by Resolution MSC. 75 (69). IMO Publishing.
  8. Karolius, K. B. and D. Vassalos(2018), Tearing down the wall - The inclining experiment. Ocean Engineering, 148, pp. 442-475. https://doi.org/10.1016/j.oceaneng.2017.11.037
  9. Nakamura, S., T. Hanawa, K. Saito, E. Misumi, and T. Yoshimura(1975), Wave Loads Acting on Connecting Device of Ocean-Going Pusher Barge in Oblique Regular Waves. Journal of the Society of Naval Architects of Japan, 1975(137), pp. 268-278. https://doi.org/10.2534/jjasnaoe1968.1975.268
  10. Nowacki, H. and L. D. Ferreiro(2003), Historical roots of the theory of hydrostatic stability of ships, Max-Planck-Institut fur Wissenschaftsgeschichte.
  11. Taylan, M.(2020), Reliability analysis of GM and KG of ships from the inclining experiment. Proceedings of the Institution of Mechanical Engineers, Part M: Journal of Engineering for the Maritime Environment, 234(4), pp. 803-809. https://doi.org/10.1177/1475090220913709
  12. Zeraatgar, H., M. Asghari, and F. Bakhtiari-Nejad(2010), A study of the roll motion by means of a free decay test. Journal of Offshore Mechanics and Arctic Engineering, 132(3).