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Viscous attenuation of mean drift in water waves

Published online by Cambridge University Press:  12 April 2006

An-Kuo Liu
Affiliation:
Department of Mechanics and Materials Science, The Johns Hopkins University, Baltimore, Maryland 21218 Present address: Dynamics Technology, Inc., Torrance, California 90503.
Stephen H. Davis
Affiliation:
Department of Mechanics and Materials Science, The Johns Hopkins University, Baltimore, Maryland 21218

Abstract

The initial-value problem for slightly viscous, two-dimensional, spatially periodic waves is examined. Matched asymptotic expansions in space for small wave amplitude a and multiple scales in time allow the boundary layers and viscous attenuation to be described. The bottom and surface boundary layers of thickness δ are equivalent to those of Longuet-Higgins except that wave attenuation is included. For progressive waves one solution for the interior motion independent of the magnitude of δ/a is an attenuating version of the conduction solution of Longuet-Higgins, but with modified structure, the O(a2) vorticity at the boundaries ultimately diffusing into the entire field. There are certain critical depths for which there is secular behaviour and these do not correspond to quasi-steady flows. Other solutions may be possible. For standing waves the interior flow depends on the magnitude of the steady-drift Reynolds number Rs∝ (a/δ)2 introduced by Stuart. When Rs [Lt ] 1, the interior is viscous with an O(a2) vorticity ultimately diffusing into the entire field. When Rs [Gt ] 1 there is a doubleboundary-layer structure on the bottom and on the surface. Within the outer layers, the O(a2) steady drift decays to the potential flow interior. A direct analogy with the flow structure on a circular cylinder oscillating along its diameter is introduced and pursued. Finally, all of the above fields are converted to Lagrangian fields so that masstransport profiles can be obtained. Comparisons are made with previous theoretical and experimental work.

Type
Research Article
Copyright
© 1977 Cambridge University Press

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References

Bagnold, R. A. 1947 Sand movement by waves: some small-scale experiments with sand of very low density. J. Inst. Civil Engrs Lond. 27, 447469.Google Scholar
Bickley, W. G. 1937 The plane jet. Phil. Mag. 23, 727.Google Scholar
Caligny, A. F. H. De 1878 Expériences sur les mouvements des molécules liquides des ondes courantes, considérées dans leur mode d'action sur la marche des navires. C.R. Acad. Sci. Paris 87, 10191023.Google Scholar
Davidson, B. J. & Riley, N. 1972 Jets induced by oscillatory motion. J. Fluid Mech. 53, 287.Google Scholar
Dore, B. D. 1971 A study of mass transport in boundary layers at oscillatory free surface and interface. Proc. IUTAM Symp. Unsteady Boundary Layers. University of Laval Press.
Dore, B. D. 1974 The mass transport velocity due to interacting wave trains. Meccanica 9, 172.Google Scholar
Dore, B. D. 1975 Wave-induced vorticity in free-surface boundary layers: application to mass transport in edge waves. J. Fluid Mech. 70, 257266.Google Scholar
Harrison, W. J. 1909 The influence of viscosity and capillarity on waves of finite amplitude. Proc. Lond. Math. Soc. (2), 7, 107–121.
Huang, N. E. 1970 Mass transport induced by wave motion. J. Mar. Res. 28, 3550.Google Scholar
Hunt, J. N. & Massoud, S. K. A. 1962 On mass transport in deep water waves. Pure Appl. Geophys. 53, 6576.Google Scholar
Lamb, H. 1932 Hydrodynamics, 6th edn. Cambridge University Press.
Longuet-Higgins, M. S. 1953 Mass transport in water waves. Phil. Trans. Roy. Soc. A 245, 535581.Google Scholar
Longuet-Higgins, M. S. 1960 Mass transport in the boundary layer at a free oscillating surface. J. Fluid Mech. 8, 293306.Google Scholar
Nayfeh, A. 1973 Perturbation Methods. Interscience.
Noda, H. 1968 A study on mass transport in boundary layers in standing waves. Proc. 11th Conf. Coastal Engng, London.
Phillips, O. M. 1966 The Dynamics of the Upper Ocean. Cambridge University, Press.
Russell, R. C. H. & Osorio, J. D. C. 1957 An experimental investigation of drift profiles in a closed channel. Proc. 6th Conf. Coastal Engng, Miami, Counc. Wave Res., Univ. California, pp. 171193.
Sleath, J. F. A. 1973 Mass-transport in water waves of very small amplitude. J. Hydraul. Res. 11, 369.Google Scholar
Stokes, G. G. 1847 On the theory of oscillatory waves. Trans. Camb. Phil. Soc. 8, 441455.Google Scholar
Stuart, J. T. 1966 Double boundary layers in oscillatory viscous flow. J. Fluid Mech. 24, 673.Google Scholar
ünlüata, U. & Mei, C. C. 1970 Mass transport in water waves. J. Geophys. Res. 75, 76117618.Google Scholar
Wehausen, J. V. & Laitone, E. V. 1960 Surface Waves. Handbuch der Physik, vol. IX. Springer.