Effect of ship bow overhang on water shipping for ship advancing in regular head waves

Abstract

This paper presents the results of an experimental investigation dealing with the effect of bow overhang extensions on the quantity of shipping water over the foredeck in case of ships advancing in regular head waves. To perform this investigation, a series of free-running tests was conducted in regular waves using an experimental model of a multipurpose cargo ship to quantify the amount of shipping water. The tests were performed on five bow overhang variants with several combinations of wavelength and ship speed conditions. It was observed that the quantity of shipping water was affected by some parameters such as wavelength, ship speed, and bow shape in terms of an overhang extension. The results show the significant influence of an overhang extension, which is associated with the bow flare shape, on the occurrence of water shipping. These results involve the combined incoming regular waves and model speed.

Keywords

water on deck / shipped water amount / ship model tests / bow overhang / green water / regular head waves

References

[1] Barcellona M, Landrini M, Greco M, Faltinsen O. An experimental investigation on bow water shipping. Journal of Ship Research, 2003, 127(4): 322-330

[2] Bellez CA, Cheng LY, Nishimoto K. A numerical study of the effects of bow shape on green water phenomenon, 2013, 13-498

[3] Buchner B. The impact of green water on FPSO design. OTC1995, 1995, 7698

[4] Buchner B. The influence of the bow shape of FPSOs on the drift forces and green water. OTC1996, 1996, 8073

[5] Buchner B. A new method for the prediction of non-linear relative wave motions, 1998, 98-0592

[6] Buchner B, Voogt A. The effect of bow flare angle on FPSO green water loading. Offshore Mechanics and Arctic Engineering, 2000, 247-254

[7] Fonseca N G, Soares C. Experimental investigation of the shipping of water on the bow of a containership. Journal of Offshore Mechanics and Arctic Engineering, 2005, 127(4): 118-147

[8] Greco M, Bouscasse B, Lugni C. 3-D seakeeping analysis with water on deck and slamming. Experiments and physical investigation. Journal of Fluids and Structures, 2012, 33: 148-179

[9] Greco M, Lugni C. 3-D seakeeping analysis with water on deck and slamming. Part 1: Numerical solver. Journal of Fluids and Structures, 2012, 33: 127-147

[10] Greco M, Colicchio G, Faltinsen OM. Shipping of water on a two-dimensional structure. Journal of Fluid Mechanics, 2007, 581: 371-399

[11] Hamoudi B. experimental investigation of deck wetness for container ship. Hydrodynamics Laboratory NAOE, 1993, 109-116

[12] IMO Sensitivity of wetness and deck loads to bow height and forward buoyancy reserves in extreme weather conditions, 1999

[13] Kazuya S, Seiichi K, Katsuji T. Three-dimensional numerical analysis of shipping water onto a moving ship using a particle method. Journal of Marine Science and Technology, 2009, 14: 214-227

[14] Lloyd ARJM, Salsich JO, Zseleczky JJ. The effect of bow shape on deck wetness in head seas. The Royal Institution of Naval Architects,Trans., 1985, 9-25

[15] O'Dea JF, Walden DA. Effect of bow shape and non-linearities on the prediction of large amplitude motions and deck wetness. Proc. 15th Symp. Naval Hydro., 1984, 163-176

[16] Ogawa Y, Yoshitaka O, Makiko M, Katsuji T. Shipping water load due to deck wetness. Proceedings of The Twelfth International Offshore and Polar Engineering Conference, 2002, 26-31

[17] Ogawa Y. Long-term prediction method for the green water load and volume for an assessment of the load line. Journal of Marine Science and Technology, 2012, 7: 137-144

[18] Pham XP. Green water and loading on high speed containerships, 2008

[19] Rainey RCT. Weak or strong nonlinearity: the vital issue. Journal of Engineering Mathematics, 2007, 58: 229-249

[20] Standing RG. Green seas damage on FPSOs and FSUs. HSE report OTH, 1997, 486

[21] Watanabe I, Ueno M, Sawada H. Effects of bow fare shape on wave loads of a container ship. Journal of the Society of Naval Architects of Japan, 1989, 66: 259-266