Hostname: page-component-78c5997874-94fs2 Total loading time: 0 Render date: 2024-11-18T15:30:12.722Z Has data issue: false hasContentIssue false

On shoaling of solitary waves

Published online by Cambridge University Press:  13 June 2018

Jeffrey Knowles
Affiliation:
School of Civil and Construction Engineering, Oregon State University, Corvallis, OR 97331, USA
Harry Yeh*
Affiliation:
School of Civil and Construction Engineering, Oregon State University, Corvallis, OR 97331, USA
*
Email address for correspondence: harry@oregonstate.edu

Abstract

One of the classic analytical predictions of shoaling-wave amplification is Green’s law – the wave amplitude grows proportional to $h^{-1/4}$, where $h$ is the local water depth. Green’s law is valid for linear shallow-water waves unidirectionally propagating in a gradually varying water depth. On the other hand, conservation of mechanical energy shows that the shoaling-wave amplitude of a solitary wave grows like $a\propto h^{-1}$, if the waveform maintains its solitary-wave identity. Nonetheless, some recent laboratory and field measurements indicate that growth of long waves during shoaling is slower than what is predicted by Green’s law. Obvious missing factors in Green’s law are the nonlinearity and frequency-dispersion effects as well as wave reflection from the beach, whereas the adiabatic shoaling process does not recognize the transformation of the waveform on a beach of finite slope and length. Here we first examine this problem analytically based on the variable-coefficient perturbed Korteweg–de Vries equation. Three analytical solutions for different limits are obtained: (1) Green’s law for the linear and non-dispersive limit, (2) the slower amplitude growth rate for the linear and dispersive limit, as well as (3) nonlinear and non-dispersive limit. Then, in order to characterize the shoaling behaviours for a variety of incident wave and beach conditions, we implement a fifth-order pseudo-spectral numerical model for the full water-wave Euler theory. We found that Green’s law is not the norm but is limited to small incident-wave amplitudes when the wavelength is still small in comparison to the beach length scale. In general, the wave amplification rate during shoaling does not follow a power law. When the incident wave is finite, the shoaling amplification becomes faster than that of Green’s law when the ratio of the wavelength to the beach length is small, but becomes slower when the length ratio increases. We also found that the incident wave starts to amplify prior to its crest arriving at the beach toe due to the wave reflection. Other prominent characteristics and behaviours of solitary-wave shoaling are discussed.

Type
JFM Papers
Copyright
© 2018 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

Battjes, J. A. 1974 Coastal Engineering Proceedings, vol. 1, pp. 466480. ASCE.Google Scholar
Bona, J. L., Chen, M. & Saut, J.-C. 2002 Boussinesq equations and other systems for small-amplitude long waves in nonlinear dispersive media. 1: derivation and linear theory. J. Nonlinear Sci. 12, 283318.Google Scholar
Bowen, A. J., Inman, D. L. & Simons, V. P. 1968 Wave ‘set-down’ and set-up. J. Geophys. Res. 73 (8), 25692577.Google Scholar
Boyce, W. E. & DiPrima, R. C. 2009 Elementary Differential Equations and Boundary Value Problems, 9th edn. Wiley.Google Scholar
Camfield, F. E. & Street, R. I. 1969 Shoaling of solitary waves on small slopes. ASCE J. Waterway Port Coastal Ocean Engng 95, 122.Google Scholar
Chan, R. K. C. & Street, R. L. 1970 A computer study of finite-amplitude water waves. J. Comput. Phys. 6, 6894.Google Scholar
Craig, W. & Sulem, C. 1993 Numerical simulation of gravity waves. J. Comput. Phys. 108 (1), 7383.Google Scholar
Dommermuth, D. G. & Yue, K. P. 1987 A high-order spectral method for the study of nonlinear gravity waves. J. Fluid Mech. 184, 267288.Google Scholar
El, G. A., Grimshaw, R. H. J. & Kamchatnov, A. M. 2007 Evolution of solitary waves and undular bores in shallow-water flows over a gradual slope with bottom friction. J. Fluid Mech. 585, 213244.Google Scholar
Elgar, S., Freilich, M. H. & Guza, R. T. 1990 Model–data comparisons of moments of nonbreaking shoaling surface gravity waves. J. Geophys. Res. 95, 1605516063.Google Scholar
Flick, R. E., Guza, R. T. & Inman, D. L. 1981 Elevation and velocity measurements of laboratory shoaling waves. J. Geophys. Res. 86, 41494160.Google Scholar
Grilli, S. T., Subramanya, R., Svendsen, I. A. & Veeramony, J. 1994 Shoaling of solitary waves on plane beaches. ASCE J. Waterway Port Coastal Ocean Engng 120, 609628.Google Scholar
Grilli, S. T., Svendsen, I. A. & Subramanya, R. 1997 Breaking criterion and characteristics for solitary wavs on slopes. ASCE J. Waterway Port Coastal Ocean Engng 123, 102112.Google Scholar
Grimshaw, R. 1971 The solitary wave in water of variable depth. Part 2. J. Fluid Mech. 46 (3), 611622.Google Scholar
Grimshaw, R. 1981 Evolution equations for long nonlinear internal waves in stratified shear flows. Stud. Appl. Maths 65, 159188.Google Scholar
Hsiao, S. C., Hsu, T. W., Lin, T. C. & Chang, Y. H. 2008 On the evolution and run-up of breaking solitary waves on a mild sloping beach. Coast. Engng 55, 975988.Google Scholar
Ippen, A. T. & Kulin, G. 1954 The shoaling and breaking of the solitary wave. In Proceedings of the 5th Coastal Engineering Conference, vol. 1, pp. 2747. ASCE.Google Scholar
Johnson, R. S. 1973a On the development of a solitary wave moving over an uneven bottom. Proc. Camb. Phil. Soc. 73, 183203.Google Scholar
Johnson, R. S. 1973b On an asymptotic solution of the Korteweg–de Vries equation with slowly varying coefficients. J. Fluid Mech. 60, 813824.Google Scholar
Kakutani, T. R. 1971 Effect of an uneven bottom on gravity waves. J. Phys. Soc. Japan 30, 272276.Google Scholar
Kalisch, H. & Senthilkumar, A. 2013 A derivation of Boussinesq’s shoaling law using a coupled BBM system. Nonlinear Process. Geophys. 20, 213219.Google Scholar
Ko, H. & Yeh, H. 2018 On the splash-up of tsunami bore impact. Coast. Engng 131, 111.Google Scholar
Lamb, H. 1932 Hydrodynamics. Cambridge University Press.Google Scholar
Madsen, P. A., Fuhrman, D. R. & Schäffer, H. A. 2008 On the solitary wave paradigm for tsunamis. J. Geophys. Res. 113 (12), 122.Google Scholar
Madsen, P. A. & Schäffer, H. A. 2010 Analytical solutions for tsunami runup on a plane beach: single waves, n-waves and transient waves. J. Fluid Mech. 645, 2757.Google Scholar
Madsen, P. A. & Sørensen, O. R. 1992 A new form of the Boussinesq equations with improved linear dispersion characteristics. Part 2. A slowly-varying bathymetry. Coast. Engng 18, 183204.Google Scholar
McCowan, J. 1891 VII. On the solitary wave. London, Edinb. Dublin Philos. Mag. J. Sci. 32 (194), 4558.Google Scholar
Miles, J. W. 1979 On the Korteweg–de Vries equation for a gradually varying channel. J. Fluid Mech. 91, 181190.Google Scholar
Miles, J. W. 1983 Solitary wave evolution over a gradual slope with turbulent friction. J. Phys. Oceanogr. 13, 551553.Google Scholar
PARI2011 Port and airport research institute. Tech. Note No. 1231.Google Scholar
Peregrine, D. H. 1967 Long waves on a beach. J. Fluid Mech. 27, 815827.Google Scholar
Pujara, N., Liu, P. L. F. & Yeh, H. 2015 The swash of solitary waves: flow evolution, bed shear stress and run-up. J. Fluid Mech. 779, 556597.Google Scholar
Shuto, N. 1973 Shoaling and deformation of non-linear long waves. Coast. Engng Japan 16, 112.CrossRefGoogle Scholar
Street, R. L. & Camfield, F. E. 1966 Observations and experiments on solitary wave deformation. In Proceedings 10th Conference on Coastal Engineering, pp. 284301. ASCE.Google Scholar
Synolakis, C. E. 1990 Green’s law and the evolution of solitary waves. Phys. Fluids A 3, 490491.Google Scholar
Synolakis, C. E. & Skjelbreia, J. E. 1993 Evolution of maximum amplitude of solitary waves on plane beaches. ASCE J. Waterway Port Coastal Ocean Engng 119, 323342.Google Scholar
Whitham, G. B. 1965 Nonlinear dispersive waves. Proc. R. Soc. Lond. A 283, 238261.Google Scholar
Yeh, H., Liu, P. & Synolakis, C. 1996 Long-Wave Runup Models, p. 403. World Scientific.Google Scholar
Yeh, H., Sato, S. & Tajima, Y. 2011 Waveform evolution of the 2011 east Japan tsunami. In Asian and Pacific Coasts 2011: Proceedings of the 6th International Conference on APAC 2011 (ed. Lee, C.-O. & Ng, J. H.-W.), pp. 5970. World Scientific.Google Scholar
Zakharov, V. E. 1968 Stability of periodic waves of finite amplitude on the surface of a deep fluid. J. Appl. Mech. Tech. Phys. 9 (2), 190194.CrossRefGoogle Scholar