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Wave forces on three-dimensional floating bodies with small forward speed

Published online by Cambridge University Press:  26 April 2006

Jan Nossen ,
John Grue  and
Enok Palm
Jan Nossen
Affiliation:
Department of Mathematics, University of Oslo, Norway
John Grue
Affiliation:
Department of Mathematics, University of Oslo, Norway
Enok Palm
Affiliation:
Department of Mathematics, University of Oslo, Norway
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Abstract

A boundary-integral method is developed for computing first-order and mean second-order wave forces on floating bodies with small forward speed in three dimensions. The method is based on applying Green's theorem and linearizing the Green function and velocity potential in the forward speed. The velocity potential on the wetted body surface is then given as the solution of two sets of integral equations with unknowns only on the body. The equations contain no water-line integral, and the free-surface integral decays rapidly. The Timman-Newman symmetry relations for the added mass and damping coefficients are extended to the case when the double-body flow around the body is included in the free-surface condition. The linear wave exciting forces are found both by pressure integration and by a generalized far-field form of the Haskind relations. The mean drift force is found by far-field analysis. All the derivations are made for an arbitrary wave heading. A boundary-element program utilizing the new method has been developed. Numerical results and convergence tests are presented for several body geometries. It is found that the wave exciting forces and the mean drift forces are most influenced by a small forward speed. Values of the wave drift damping coefficient are computed. It is found that interference phenomena may lead to negative wave drift damping for bodies of complicated shape.

Type
Research Article
Information
Journal of Fluid Mechanics , Volume 227 , June 1991 , pp. 135 - 160
Copyright
© 1991 Cambridge University Press

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References

Faltinsen, O. M. 1990 Sea Loads on Ships and Offshore Structures. Cambridge University Press.
Grue, J. & Palm, E. 1990 Mean forces on floating bodies in waves and current. Proc. 5th Intl Workshop on Water Waves and Floating Bodies, Manchester, U.K..
Haskind, M. D. 1946 The hydrodynamic theory of ships oscillating in rolling and pitching. Prikl. Mat. Mekh. 10, 33–66.Google Scholar
Huijsmans, R. H. M. & Hermans, A. J. 1985 A fast algorithm for computation of 3-D ship motions at moderate forward speed. 4th Intl Conf. on Numerical Ship Hydrodynamics.
Maruo, H. 1960 Wave resistance of a ship in regular head sea. Bulletin of the Faculty of Engineering, Yokohama National University, vol. 9.
Newman, J. N. 1959 The damping and wave resistance of a pitching and heaving ship. J. Ship Res. 3, 1–19.Google Scholar
Newman, J. N. 1977 Marine Hydrodynamics. The MIT Press.
Newman, J. N. 1978 The theory of ship motions. Adv. Appl. Mech. 18, 221–280.Google Scholar
Newman, J. N. 1984 An expansion of the oscillatory source potential. Appl. Ocean Res. 6, 116–117.Google Scholar
Newman, J. N. & Sclavounos, P. D. 1987 WAMIT User's Manual. MIT.
Ogilvie, T. F. & Tuck, E. O. 1969 A rational strip theory of ship motions: part 1. Rep. 013. The Department of Naval Architecture and Marine Engineering, The University of Michigan, College of Engineering.
Schellin, T. E. & Kirsch, A. 1989 Low-frequency damping of a moored semisubmersible obtained from simulated extinction tests and mean wave drift forces. Appl. Ocean Res. 11, 202–211.Google Scholar
Timman, R. & Newman, J. N. 1962 The coupled damping coefficients of a symmetric ship. J. Ship Res. 5, 1–7.Google Scholar
Wichers, J. E. W. & Huijsmans, R. H. M. 1984 On the low frequency hydrodynamic damping forces acting on offshore moored vessels. Proc. Offshore Technology Conf., Houston, OTC 4831.
Wichers, J. E. W. & Sluijs, M. F. 1979 The influence of waves on the low frequency hydrodynamic coefficients of moored vessels. Proc. Offshore Technology Conf., Houston, OTC 3625.
Wu, G. X. & Eatock-Taylor, R. 1990 The hydrodynamic force on an oscillating ship with low forward speed. J. Fluid Mech. 211, 333–353.Google Scholar
Zhao, R. & Faltinsen, O. M. 1988 Interaction between waves and current on a 2-D body in the free surface. Appl. Ocean Res. 10, 87–99.Google Scholar
Zhao, R. & Faltinsen, O. M. 1989 Interaction between current, waves and marine structures. 5th Intl Conf. on Numerical Ship Hydrodynamics.
Zhao, R., Faltinsen, O. M., Krokstad, J. R. & Aanesland, V. 1988 Wave-current interaction effects on large-volume structures. Proc. Intl Conf. on the Behaviour of Offshore Structures (ed. T. Moan, N. Janbu & O. Faltinsen), vol. 2, pp. 623–638. Trondheim: Tapir Publishers.