Hostname: page-component-cd9895bd7-q99xh Total loading time: 0 Render date: 2024-12-20T20:42:36.444Z Has data issue: false hasContentIssue false

Dispersive dam-break and lock-exchange flows in a two-layer fluid

Published online by Cambridge University Press:  14 January 2011

J. G. ESLER*
Affiliation:
Department of Mathematics, University College London, 25 Gower Street, London WC1E 6BT, UK
J. D. PEARCE
Affiliation:
Department of Mathematics, University College London, 25 Gower Street, London WC1E 6BT, UK
*
Email address for correspondence: [email protected]

Abstract

Dam-break and lock-exchange flows are considered in a Boussinesq two-layer fluid system in a uniform two-dimensional channel. The focus is on inviscid ‘weak’ dam breaks or lock exchanges, for which waves generated from the initial conditions do not break, but instead disperse in a so-called undular bore. The evolution of such flows can be described by the Miyata–Camassa–Choi (MCC) equations. Insight into solutions of the MCC equations is provided by the canonical form of their long wave limit, the two-layer shallow water equations, which can be related to their single-layer counterpart via a surjective map. The nature of this surjective map illustrates that whilst some Riemann-type initial-value problems (dam breaks) are analogous to those in the single-layer problem, others (lock exchanges) are not. Previous descriptions of MCC waves of permanent form (cnoidal and solitary waves) are generalised, including a description of the effects of a regularising surface tension. The wave solutions allow the application of a technique due to El's approach, based on Whitham's modulation theory, which is used to determine key features of the expanding undular bore as a function of the initial conditions. A typical dam-break flow consists of a leftwards-propagating simple rarefaction wave and a rightward-propagating simple undular bore. The leading and trailing edge speeds, leading edge solitary wave amplitude and trailing edge linear wavelength are determined for the undular bore. Lock-exchange flows, for which the initial interface shape crosses the mid-depth of the channel, by contrast, are found to be more complex, and depending on the value of the surface tension parameter may include ‘solibores’ or fronts connecting two distinct regimes of long-wave behaviour. All of the results presented are informed and verified by numerical solutions of the MCC equations.

Type
Papers
Copyright
Copyright © Cambridge University Press 2011

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

REFERENCES

Baines, P. G. 1984 A unified description of two-layer flow over topography. J. Fluid Mech. 146, 127167.Google Scholar
Baines, P. G. 1995 Topographic Effects in Stratified Flows. Cambridge University Press.Google Scholar
Benjamin, T. B. 1968 Gravity currents and related phenomena. J. Fluid Mech. 31, 209248.CrossRefGoogle Scholar
Benjamin, T. B. & Lighthill, M. J. 1954 On cnoidal waves and bores. Proc. R. Soc. Lond. A 224, 448460.Google Scholar
Buckley, S. E. & Leverett, M. C. 1942 Mechanism of fluid displacements in sands. Trans. AIME 141, 107116.CrossRefGoogle Scholar
Cavanie, A. G. 1969 Sur la genese et la propagation d'ondes internes dans un millieu a deux couches. Cahiers Océanographiques, 9, 831843.Google Scholar
Choi, W., Barros, R. & Jo, T.-C. 2009 A regularized model for strongly nonlinear internal solitary waves. J. Fluid Mech. 629, 7385.CrossRefGoogle Scholar
Choi, W. & Camassa, R. 1999 Fully nonlinear internal waves in a two-fluid system. J. Fluid Mech. 396, 136.Google Scholar
Chu, V. H. & Baddour, R. E. 1977 Surges, waves and mixing in two-layer density stratified flow. Proc. 17th Congr. Intl Assoc. Hydraul. Res. 1, 303310.Google Scholar
Chumakova, L., Menzaque, F. E., Milewski, P. A., Rosales, R. R., Tabak, E. G. & Turner, C. V. 2009 Stability properties and nonlinear mappings of two and three layer stratified flows. Stud. Appl. Maths 122, 123137.CrossRefGoogle Scholar
Clarke, J. C. 1998 An atmospheric undular bore along the Texas coast. Mon. Weath. Rev. 126, 10981100.2.0.CO;2>CrossRefGoogle Scholar
El, G. A. 2005 Resolution of a shock in hyperbolic systems modified by weak dispersion. Chaos 15, 037103.CrossRefGoogle ScholarPubMed
El, G. A., Grimshaw, R. H. J. & Smyth, N. F. 2006 Unsteady undular bores in fully nonlinear shallow-water theory. Phys. Fluids 18, 027104.CrossRefGoogle Scholar
El, G. A., Grimshaw, R. H. J. & Smyth, N. F. 2009 Transcritical shallow water flow past topography: finite-amplitude theory. J. Fluid Mech. 640, 187215.CrossRefGoogle Scholar
El, G. A., Khodorovskii, V. V. & Tyurina, A. V. 2003 Determination of boundaries of unsteady oscillatory zone in asymptotic solutions of non-integrable dispersive wave equations. Phys. Lett. A 318, 526536.Google Scholar
El, G. A., Khodorovskii, V. V. & Tyurina, A. V. 2005 Undular bore transition in bi-directional conservative wave dynamics. Physica D 206, 232251.Google Scholar
Favre, H. 1935 Etude Théoretique et Éxperimentale des Ondes de Translation dans les Canaux Decouverte. Dunod.Google Scholar
Grimshaw, R. 2002 Internal solitary waves. In Environmental Stratified Flows, chap. 1, pp. 128. Kluwer.Google Scholar
Grimshaw, R., Pelinovsky, D., Pelinovsky, E. & Slunyaev, A. 2002 The generation of large-amplitude solitons from an initial disturbance in the extended Korteweg–de Vries equation. Chaos 12, 10701076.CrossRefGoogle ScholarPubMed
Gurevich, A. V. & Pitaevskii, L. P. 1974 Nonstationary structure of a collisionless shock wave. Sov. Phys. JETP 38, 291297.Google Scholar
Holloway, P., Pelinovsky, E. & Talipova, T. 2001 Internal tide transformation and oceanic internal solitary waves. In Environmental Stratified Flows, chap. 2, pp. 2960. Kluwer.Google Scholar
Hosegood, P. & van Haren, H. 2004 Near-bed solibores over the continental slope in the Faroe-Shetland channel. Deep-sea Res. II 51, 29432971.Google Scholar
Kamchatnov, A. N. 2000 Nonlinear Periodic Waves and Their Modulations – An Introductory Course. World Scientific.Google Scholar
Klemp, J. B., Rotunno, R. & Skamarock, W. C. 1994 On the dynamics of gravity currents in a channel. J. Fluid Mech. 269, 169198.Google Scholar
Klemp, J. B., Rotunno, R. & Skamarock, W. C. 1997 On the propagation of internal bores. J. Fluid Mech. 331, 81106.Google Scholar
Laget, O. & Dias, F. 1997 Numerical computation of capillary-gravity interfacial solitary waves. J. Fluid Mech. 349, 221251.CrossRefGoogle Scholar
Li, M. & Cummins, P. F. 1998 A note on hydraulic theory of internal bores. Dyn. Atmos. Oceans 28, 17.Google Scholar
Liska, R., Margolin, L. & Wendroff, B. 1995 Nonhydrostatic two-layer models of incompressible flow. Comput. Math. Appl. 29, 2537.Google Scholar
MacKinnon, J. A. & Gregg, M. C. 2003 Shear and baroclinic energy flux on the summer New England shelf. J. Phys. Oceanogr. 33, 14621475.Google Scholar
Milewski, P. A., Tabak, E. G., Turner, C. V., Rosales, R. R. & Menzaque, F. E. 2004 Nonlinear stability of two-layer flows. Commun. Math Sci. 2, 427442.Google Scholar
Miyata, M. 1985 An internal solitary wave of large amplitude. La Mer 23, 4348.Google Scholar
Pearce, J. D. 2009 Dispersive phenomena in extended shallow water models of geophysical flows. PhD thesis, Senate House Library, University of London, London, UK.Google Scholar
Rottman, J. W. & Grimshaw, R. 2002 Atmospheric internal solitary waves. In Environmental Stratified Flows, chap. 3, pp. 6188. Kluwer.Google Scholar
Rottman, J. W. & Simpson, J. E. 1983 Gravity currents produced by instantaneous releases of a heavy fluid in a rectangular channel. J. Fluid Mech. 135, 95110.CrossRefGoogle Scholar
Rottman, J. W. & Simpson, J. E. 1989 The formation of internal bores in the atmosphere: a laboratory model. Q. J. R. Meteorol. Soc. 115, 941963.CrossRefGoogle Scholar
Sandstrom, H. & Quon, C. 1993 On time-dependent, two-layer flow over topography. Part I. Hydrostatic approximation. Fluid Dyn. Res. 11, 119137.Google Scholar
Shin, J. O., Dalziel, S. B. & Linden, P. F. 2005 Gravity currents produced by lock exchange. J. Fluid Mech. 521, 134.Google Scholar
Su, C. H. & Gardner, C. S. 1969 Korteweg-de Vries equation and generalizations. Part III. Derivation of the Korteweg-de Vries equation and Burgers equation. J. Math. Phys. 10, 536.CrossRefGoogle Scholar
Whitham, G. B. 1965 Non-linear dispersive waves. Proc. R. Soc. Lond., Ser. A 283, 238291.Google Scholar
Wood, I. R. & Simpson, J. E. 1984 Jumps in layered miscible fluids. J. Fluid Mech. 140, 215231.CrossRefGoogle Scholar
Zahibo, N., Slunyaev, A., Talipova, T., Pelinovsky, E., Kurkin, A. & Polukhina, O. 2007 Strongly nonlinear steepening of long interfacial waves. Nonlinear Process. Geophys. 14, 247256.Google Scholar