Estimation of moonpool influence on heave and pitch ship motions in head waves

Author: K.D. Ovchinnikov

Abstract

The paper presents results of analysis of circle-section moonpool influence on heave and pitch ship motions in head waves using experimental research and computational fluid dynamics (CFD). The experimental research was conducted in model ship basin of St. Petersburg State Marine Technical University. Heave and pitch motions of series 60 vessel with different types of moonpool were tested on regular head waves. As a result, of experiments RAO of heave and pitch motions and vertical water motions in the moonpool were obtained. Numerical simulation was conducted using OpenFOAM open source CFD software. Heave and pitch motions were calculated for series 60 and DTMB 5415 hulls with different circle-section moonpools (with diameters up to half of hull beam), located near ship center of buoyancy. Additionally, heave and pitch motions of series 60 hull with circle-section moonpool with 25 % hull beam diameter were calculated for different moonpool locations on the ship length. Finally, RAO of heave and pitch motions depending on hull forms and moonpool dimensions and locations were obtained. The study has concluded that moonpool has very little influence on heave and pitch ship motions in head waves. Motions of ship with moonpool can be calculated as those for the naked hull.

Keywords: heave and pitch motions, moonpool, series 60, DTMB 5415, RAO, OpenFOAM.

References

Gaillarde G. and Cotteleer A., Water motion in moonpools empirical and theoretical approach, Maritime Research Institute Netherlands MARIN, 2001.
Fukuda K. Behaviour of water in vertical well with bottom opening of ship, and its effect on ship motions, Journal of the Society of Naval Architects of Japan, Vol. 141, pp. 107-122, 1977.
Aalbers A.B. The water motions in a moonpool, Ocean Engineering, Vol. 11, No. 6, pp. 557-579, 1984.
Matusiak J. Water column motion in a moonpool of a ship. Journal for Structural Mechanics. Vol. 30 1997, No 2.
Molin B. On sloshing modes in square or nearly square moonpools. 33rd International Workshop on Water Waves and Floating Bodies, April 4 to April 7, 2018 in Guidel-Plages, FRANCE.
Molin, B. On the piston and sloshing modes in moonpools, Journal of Fluid Mechanics, Vol. 430, pp. 27-50, Cam-bridge University Press, 2001.
Molin B. On the piston mode in moonpools, Proceedings of the 14 th Int. Workshop on water waves & floating bodies, 1999.
Heo Jae-Kyung, Park, Jong-Chun, Koo, Weon-Cheol, and Kim, Moo-Hyun Influences of Vorticity to Vertical Motion of Two-Dimensional Moonpool under Forced Heave Motion. Hindawi Publishing Corporation, Mathematical Problems in Engineering, Volume 2014, Article ID 424927, 13 pp.
Malta, E.B., Cueva, M., Nishimoto, K., Gonçalves, R., Masetti, I., 2006, Numerical Moonpool Modeling, OMAE2006-92456.
Sajjan, Sharanabasappa C., and Surendran, S. Model tests on the moored vessel with different moonpool shapes, Ocean Systems Engineering Volume 3, Number 2, June 2013, pages 137-147.
Guidelines for Moonpool Assessment. Guidance Note NI 621 DT R00 E. Bureau Veritas, 2016.
Modelling and Analysis of Marine Operations. DNV-RP-H103. Det Norske Veritas as, 2014.
ITTC – Recommended Procedures and Guidelines. Seakeeping Experiments. 7.5-02 07-02.1. 2014.
https://openfoam.org/ (accessed on 21.03.2019 г.).
Blischik A.E., Taranov A.E. Chislennoe modelirovanie dinamiki sudna v zadachakh upravlyaemosti i kachki [Numerical simulation of ship dynamics in terms of maneuvrability and motions]. Transactions of the Krylov State Research Centre. 2018; 2(384): 29–38 (in Russian).
Lobachev M.P. Issledovanie osobennostey techeniya vyazkoy zhidkosti v kormovoy okonechnosti sudov s polnymi obvodami [Study of flow specifics near sterns of ships with ample hull lines]. Transactions of the Krylov State Research Centre. № 78 (362) (in Russian).
Shevchuk I.V., Kornev N.V., Ryzhov V.A. Chislennoe modelirovanie korabel'nogo sleda na melkovod'e s ispol'zovaniem gibridnogo URANS-LES metoda [Numerical simulation of ship trace on shallow water using hybrid URANS-LES method]. Morskoy Vestnik. 2013. № 1S (10) (in Russian).
Tkachenko I.V., Tryaskin N.V. Chislennoe modelirovanie kachki sudna na regulyarnom volnenii [Simulation of the rolling of ship on the regular wave]. Marine intellectual technologies. No. 3 (21) 2013 (in Russian).
Zverkov V.N., Nikushchenko D.V. Chislennoe modelirovanie kachki dvizhushchegosya sudna na vstrechnom regulyarnom volnenii [Simulation of a fast speed boat motion in regular waves with help of CFD] № 4 (26) t. 1 2014 (in Russian).
Ovchinnikov K.D. Opredelenie gidrodinamicheskih kharakteristik sudna pri kachke s pomoshh'ju sredstv vychislitel'noj gidromehaniki [Calculations of ship motions hydrodynamic characteristics by computational fluid dynamics]. Marine intellectual technologies. № 1 (39) t. 1 2018 (in Russian).
Ovchinnikov K.D. Numerical simulation of motions of ship with moonpool in head waves. Trudy ISP RAN/Proc. ISP RAS, vol. 30, issue 5, 2018. pp. 235 – 248.
Irvine M., Longo J. and Stern F. Pitch and Heave Tests and Uncertainty Assessment for a Surface Combatant in Regular Head Waves, Journal Ship Research, Vol. 52, No. 2, June 2008, pp. 146 – 163.

About author:

K.D. Ovchinnikov - State Marine Technical University, Saint-Petersburg, e-mail: ovchinnikov_kd@mail.ru

Issue: 56/57 (2019)

For citation: K.D. Ovchinnikov. Estimation of moonpool influence on heave and pitch ship motions in head waves. Research Bulletin by Russian Maritime Register of Shipping. 2019, No. 56/57, pp. 51-56.

UDC 629.5.017.2

Pp: 51-56