Hostname: page-component-cd9895bd7-p9bg8 Total loading time: 0 Render date: 2024-12-20T07:37:27.640Z Has data issue: false hasContentIssue false

The hydrodynamic force on an oscillating ship with low forward speed

Published online by Cambridge University Press:  26 April 2006

G. X. Wu
Affiliation:
Department of Mechanical Engineering, University College London, Torrington Place, London WC1E 7JE, UK
R. Eatock Taylor
Affiliation:
Department of Mechanical Engineering, University College London, Torrington Place, London WC1E 7JE, UK Department of Engineering Science, University of Oxford, Parks Road, Oxford OX1 3PJ, UK.

Abstract

The mathematical formulation of the linearized potential theory for a slowly translating body undergoing oscillations in infinitely deep water is derived based on a perturbation series in terms of forward speed. It is shown that the hydrodynamic force on the oscillating body can be obtained from the solution of the velocity potential without forward speed, if second-order terms in forward speed are neglected. An example of a submerged circular cylinder is discussed. The numerical results are compared with the general solution of the linearized potential theory by a coupled finite-element method (Wu & Eatock Taylor 1987) which is not restricted to low forward speeds. Very good agreement is found. The nonlinear effect of the steady potential on the hydrodynamic forces is also discussed and is illustrated for a floating semicircular cylinder.

Type
Research Article
Copyright
© 1990 Cambridge University Press

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

Abramowitz, M. & Stegun, M. 1965 Handbook of Mathematical Functions. Dover.
Chang, M. S. 1977 Computations of three-dimensional ship-motions with forward speed. Second Intl Conf. on Num. Ship Hydrodyn., pp. 124135.Google Scholar
Eatock Taylor, R. & Hung, S. M. 1987 Second order diffraction forces on a vertical cylinder in regular waves. Appl. Ocean Res. 9, 1930.Google Scholar
Grue, J. & Palm, E. 1985 Wave radiation and wave diffraction from a submerged body in a uniform current. J. Fluid Mech. 151, 257278.Google Scholar
Guevel, P. & Bougis, J. 1982 Ship-motions with forward speed in infinite depth. Intl Shipbuilding Prog. 29, 103117.Google Scholar
Haskind, M. D. 1946 The hydrodynamic theory of ship oscillations in rolling and pitching. Prikl. Math. Mech. 10, 3366.Google Scholar
Huijsmans, R. H. M. 1986 Wave drift forces in current. 16th Conf. on Naval Hydrodyn.Google Scholar
Inglis, R. B. & Price, W. G. 1981 A three dimensional ship motion theory - comparison between theoretical predictions and experimental data of the hydrodynamic coefficients with forward speed. Trans. RINA 124, 141157.Google Scholar
Lamb, H. 1932 Hydrodynamics, 6th edn. Cambridge University Press.
Mei, C. C. 1982 The Applied Dynamics of Ocean Surface Waves. Wiley-Interscience.
Newman, J. N. 1965 The exciting forces on a moving body in waves. J. Ship Res. 9, 190199.Google Scholar
Newman, J. N. 1978 The theory of ship motions. Adv. Appl. Mech. 18, 221283.Google Scholar
Ogilvie, T. F. 1963 First- and second-order forces on a cylinder submerged under a free surface. J. Fluid Mech. 16, 451472.Google Scholar
Ogilvie, T. F. & Tuck, E. O. 1969 A rational strip theory for ship motions: part 1. Dept. Nov. Archit. Mar. Engng Rep. no. 013. University of Michigan.
Thorne, R. C. 1953 Multipole expansions in the theory of surface waves. Proc. Camb. Phil. Soc. 49, 707716.Google Scholar
Timman, R. & Newman, J. N. 1962 The coupled damping coefficients of a symmetric ship. J. Ship Res. 5, 17.Google Scholar
Tuck, E. O. 1965 The effect of non-linearity at the free surface on flow past a submerged cylinder. J. Fluid Mech. 22, 401414.Google Scholar
Ursell, F. 1949 On the heaving motion of a circular cylinder on the surface of a fluid. Q. J. Mech. Appl. Maths 2, 218231.Google Scholar
Wu, G. X. & Eatock Taylor, R. 1987 Hydrodynamic forces on submerged oscillating cylinders at forward speed. Proc. R. Soc. Lond. A 414, 149170.Google Scholar
Wu, G. X. & Eatock Taylor, R. 1988 Reciprocity relations for hydrodynamic coefficients of bodies with forward speed. Intl Shipbuilding Prog. 35, 145153.Google Scholar