Gemi Kesiti için Yalpa Merkezi Konumunun Yalpa Sönümüne Etkisi

YILDIZ ,Burak

doi:10.5505/jems.2018.77486

Burak YILDIZ

(Yıldız Teknik Üniversitesi, Gemi İnşaatı ve Denizcilik Fakültesi, İstanbul, Türkiye)

Journal of Eta Maritime Science

Yıl: 2018Cilt: 6Sayı: 4ISSN: 2148-9386Sayfa Aralığı: 379 - 391Metin Dili: Türkçe

DOI: https://doi.org/10.5505/jems.2018.77486

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Türkçe
İngilizce

Gemi Kesiti için Yalpa Merkezi Konumunun Yalpa Sönümüne Etkisi

Öz: Viskoz yalpa sönümünün doğru olarak hesaplanması gemilerin yalpa hareketinin analizi için önemlidir.Zorlanmış yalpa testi veya serbest bırakma testi uygulanarak gemilerin viskoz yalpa sönümü deneyselve sayısal olarak hesaplanabilir. Ayrıca deneysel veriler kullanılarak geliştirilen yarı ampirik formüllerde viskoz yalpa sönümü tahmininde kullanılabilir. Bu çalışmada bir gemi orta kesiti için yalpa merkezikonumunun yalpa sönümüne etkisi deneysel, sayısal ve Ikeda yarı ampirik metoduyla incelenmiştir.Yalpa merkezinin dikine konumu kaide hattı ve güverte hattı arasında değiştirilmiştir. Yalpa sönümkatsayıları yalpa omurgaya sahip bir gemi orta kesitine zorlanmış yalpa testi uygulanarak deneysel vesayısal (HAD yöntemi) olarak hesaplanmıştır. Ayrıca Ikeda tarafından önerilen yarı ampirik formül ilede sonuçlar karşılaştırılmıştır. Sayısal sonuçların deneyler ile uyum içinde olduğu ve Ikeda metodundandaha yaklaşık sonuçlar verdiği görülmüştür

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Effect of the Roll Center Position on the Roll Damping of a Ship Section

Öz:The accurate calculation of the viscous roll damping is important for the estimation of the ship roll motion. Viscous roll damping can be calculated experimentally or numerically using forced roll oscillation or free roll decay tests. Semi-empirical formulae derived from experiment data can also be used for the prediction of viscous roll damping. In this study, the effect of the roll center position on the roll damping of a ship midsection was investigated experimentally, numerically and by using Ikeda’s semi-empirical method. The vertical position of the roll center were shifted from near-bottom to main deck level of the ship section. The roll damping coefficients were obtained experimentally and numerically (CFD) by applying forced oscillation tests to the ship midsection with bilge keels. Semi-empirical Ikeda method was also used for the comparison of the results. It was observed that the numerical results are in good agreement with experimental results and the estimation of roll damping with numerical method is better than Ikeda method.

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Belge Türü: DergiMakale Türü: Araştırma MakalesiErişim Formatı: Erişime Açık

[1] ITTC (2011). ITTC recommended procedures numerical estimation of roll damping. In: international towing tank conference. Report 7.5- 02-07-04.5.
[2] IMO (2016). Draft explanatory notes on the vulnerability of ships to the parametric roll stability failure mode. SDC 3/WP.5, Annex 4.
[3] Ikeda, Y., Himeno, Y. ve Tanaka, N. (1978d). Components of roll damping of ship at forward speed. Report of the Department of Naval Architecture, University of Osaka Prefecture, No. 00404.
[4] Ikeda, Y., Himeno, Y. ve Tanaka, N. (1978e). A prediction method for ship roll damping. Report of the Department of Naval Architecture, University of Osaka Prefecture, No. 00405.
[5] Himeno, Y. (1981). Prediction of ship roll damping-state of the art. U. Michigan Dept. of Naval Arch. and Marine Engineering, Report 239.
[6] Kawahara, Y., Maekawa, K. Ve Ikeda, Y. (2009). A simple prediction formula of roll damping of conventional cargo ships on the basis of Ikeda’s method and its limitation. Proceedings of the 10th International Conference on Stability of Ships and Ocean Vehicles, Saint Petersburg, Russia.
[7] Korpus, R. A. ve Falzarano, J. M. (1997). Prediction of viscous ship roll damping by unsteady navier-stokes techniques. Journal of Offshore Mechanics and Arctic Engineering, 119: 108-113.
[8] Yeung, R. W, Liao, S. W. ve Roddier, D. (1998). Hydrodynamic coefficients of rolling rectangular cylinders. International Journal of Offshore and Polar Engineering, 8(4).
[9] Sarkar, T., ve Vassalos, D. (2001). A rans-based technique for simulation of the flow near a rolling cylinder at the free surface. Journal of Marine Science and Technology, 5 (2): 66-77.
[10] Bassler, C. C. (2013). Analysis and modeling of hydrodynamic components for ship roll motion in heavy weather. Doktora Tezi, Virginia Polytechnic Institute and State University.
[11] Oliveira, A. C. ve Fernandes, A. C. (2014). The nonlinear roll damping of a fpso hull. Journal of Offshore Mechanics and Arctic Engineering, 136(1), 011106.
[12] Avalos,G.O.,Wanderley,J.B.,Fernandes, A. C. ve Oliveira, A. C. (2014). Roll damping decay of a fpso with bilge keel. Ocean Engineering, 87 (111).
[13] Jiang, Y. (2014). Computational modeling in three dimensions of multi-dof ship motion in a viscous fluid. Doktora Tezi, Engineering - Mechanical Engineering in the Graduate Division of the University of California, Berkeley.
[14] Irkal, M.A.R., Nallayarasu, S. ve Bhattacharyya, S.K. (2016). CFD approach to roll damping of ship with bilge keel with experimental validation. Appl. Ocean Res. 55 1–17. doi:10.1016/j.apor.2015.11.008.
[15] Yıldız, B., Çakıcı, F., Katayama, T. ve Yılmaz, H. (2016). URANS prediction of roll damping for a ship hull section at shallow draft. Journal of Marine Science and Technology, 21 (1): 48-56.
[16] Yıldız B. ve Katayama T.(2017). Bilge keel–free surface interaction and vortex shedding effect on roll damping. Journal of Marine Science and Technology, 22(3), 432-446.
[17] Van Kampen, M. J. (2015). Bilge keel roll damping cfd and local velocities. Yüksek Lisans Tezi. Offshore and Dredging Engineering, The Delft University of Technology.
[18] Söder,C.J.,Rosen,A, veHuss, M.(2017). Ikeda revisited. Journal of Marine Science and Technology, https://doi. org/10.1007/s00773-017-0497-z.
[19] Fluent inc., FLUENT 6.1 user’s guide, 2003.
[20] Yi-Hsiang, Y.(2008). Prediction offlows around ship-shaped hull sections in roll using an unsteady Navier–Stokes solver. Doktorz Tezi, The University of Texas at Austin.
[21] Paap, M. (2005). Verification of cfd calculations with experiments on a rolling circular cylinder with bilge keels in a free surface, Master Tezi, Delft University of Technology and Bluewater Energy