Hostname: page-component-848d4c4894-wzw2p Total loading time: 0 Render date: 2024-05-30T07:26:44.541Z Has data issue: false hasContentIssue false

Time-dependent Kelvin cat-eye structure due to current–topography interaction

Published online by Cambridge University Press:  24 February 2020

Marcelo V. Flamarion
Affiliation:
UFRPE/Rural Federal University of Pernambuco, UACSA/Unidade Acadêmica do Cabo de Santo Agostinho, BR 101 Sul, 5225, Ponte dos Carvalhos, Cabo de Santo Agostinho, PE, 54503-900, Brazil
André Nachbin*
Affiliation:
IMPA/National Institute of Pure and Applied Mathematics, Est. D. Castorina, 110, Rio de Janeiro, RJ, 22460-320, Brazil
Roberto Ribeiro Jr
Affiliation:
UFPR/Federal University of Paraná, Departamento de Matemática, Centro Politécnico, Jardim das Américas, Caixa Postal 19081, Curitiba, PR, 81531-980, Brazil
*
Email address for correspondence: nachbin@impa.br

Abstract

Non-stationary, rotational, linear surface waves are considered where the underlying sheared current has constant vorticity. A time-dependent study is presented on the formation and persistence of a Kelvin cat-eye structure in the presence of bottom topography. The flow domain is two-dimensional, which allows for the use of a conformal mapping and working in a computational flat-bottom domain. In some cases an initial disturbance is prescribed, while in others the waves are generated from rest. Submarine particle dynamics numerically captures the horizontal critical layer, defined by closed orbits separating the fluid domain into two disjoint regions. In the wave’s moving frame, these recirculation regions are structured in the form of Kelvin cat-eyes. Owing to the interaction with topography, the usual travelling-wave formulation is abandoned and the critical layer is identified through a non-stationary set of equations. The respective time-dependent Kelvin cat-eye structure dynamically adjusts itself at the onset of wave–topography interaction, without losing its integrity. The formation of a Kelvin cat-eye structure is also studied in the case where the surface is initially undisturbed. Surface waves are generated from either the current–topography interaction or by a pressure distribution suddenly imposed along the free surface. Under the pressure forcing, an isolated cat-eye forms with a single recirculation region beneath the wave.

Type
JFM Papers
Copyright
© The Author(s), 2020. Published by 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

Aasen, A. & Varholm, K. 2018 Traveling gravity water waves with critical layers. J. Math. Fluid Mech. 20, 161187.CrossRefGoogle Scholar
Buhler, O. 2009 Waves and Mean Flows. Cambridge University Press.CrossRefGoogle Scholar
Chen, R. M., Walsh, S. & Wheeler, M.2019 Center manifold without a phase space for quasilinear problems in elasticity, biology and hydrodynamics. arXiv:1907.04370v1.Google Scholar
Constantin, A. 2011 Nonlinear Water Waves with Applications to Water–Current Interactions and Tsunamis, CBMS-NSF Regional Conference Series in Applied Mathematics, vol. 81. SIAM.CrossRefGoogle Scholar
Constantin, A. 2017 Nonlinear water waves: introduction and overview. Phil. Trans. R. Soc. Lond. A 376 (2111), 20170310.Google Scholar
Constantin, A., Strauss, W. & Varvaruca, E. 2016 Global bifurcation of steady gravity water waves with critical layers. Acta Math. 217, 195262.CrossRefGoogle Scholar
Constantin, A. & Villari, G. 2008 Particle trajectories in linear water waves. J. Math. Fluid Mech. 10, 118.CrossRefGoogle Scholar
Ehrnström, M., Escher, J. & Villari, G. 2012 Steady water waves with multiple critical layers: interior dynamics. J. Math. Fluid Mech. 14, 407419.CrossRefGoogle Scholar
Ehrnström, M. & Villari, G. 2008 Linear water waves with vorticity: rotational features and particle paths. J. Differ. Equ. 244, 18881909.CrossRefGoogle Scholar
Flamarion, M. V., Milewski, P. A. & Nachbin, A. 2019 Rotational waves generated by current–topography interaction. Stud. Appl. Maths 142, 433464.CrossRefGoogle Scholar
Francius, M. & Kharif, C. 2017 Two-dimensional stability of finite-amplitude gravity waves on water of finite depth with constant vorticity. J. Fluid Mech. 830, 631659.CrossRefGoogle Scholar
Henry, D. 2013 Steady periodic waves bifurcating for fixed-depth rotational flows. Q. Appl. Maths LXXI (3), 455487.CrossRefGoogle Scholar
Johnson, R. S. 1986 On the nonlinear critical layer below a nonlinear unsteady surface wave. J. Fluid Mech. 167, 327351.CrossRefGoogle Scholar
Johnson, R. S. 2012 Models for the formation of a critical layer in water wave propagation. Phil. Trans. R. Soc. Lond. A 370, 16381660.CrossRefGoogle ScholarPubMed
Ko, J. & Strauss, W. 2008 Large-amplitude steady rotational water waves. Eur. J. Mech. (B/Fluids) 27, 96109.CrossRefGoogle Scholar
Milewski, P. A. 2004 The forced Korteweg-de Vries equation as a model for waves generated by topography. CUBO Math. J. 6, 3351.Google Scholar
Milewski, P. A. & Tabak, E. G. 1999 A pseudo-spectral algorithm for the solution of nonlinear wave equations. SIAM J. Sci. Comput. 21 (3), 11021114.CrossRefGoogle Scholar
Nachbin, A. 2003 A terrain-following Boussinesq system. SIAM J. Appl. Maths 63, 905922.CrossRefGoogle Scholar
Nachbin, A. & Ribeiro, R. Jr. 2014 A boundary integral formulation for particle trajectories in Stokes waves 2014. Discrete Continuous Dyn. Syst. A 34 (8), 31353153.CrossRefGoogle Scholar
Nachbin, A. & Ribeiro, R. Jr. 2017 Capturing the flow beneath water waves. Phil. Trans. R. Soc. Lond. A 376 (2111), 20170098.Google Scholar
Ribeiro, R. Jr., Milewski, P. A. & Nachbin, A. 2017 Flow structure beneath rotational water waves with stagnation points. J. Fluid Mech. 812, 792814.CrossRefGoogle Scholar
Soontiens, N., Subich, C. & Stastna, M. 2010 Numerical simulation of supercritical trapped internal waves over topography. Phys. Fluids 22, 16605.CrossRefGoogle Scholar
Teles da Silva, A. F. & Peregrine, D. H. 1988 Steep, steady surface waves on water of finite depth with constant vorticity. J. Fluid Mech. 195, 281302.CrossRefGoogle Scholar
Trefethen, L. N. 2001 Spectral Methods in MATLAB. SIAM.Google Scholar
Vasan, V. & Oliveras, K. 2014 Pressure beneath a traveling wave with vorticity constant. Discrete Continuous Dyn. Syst. A 34 (8), 32193239.CrossRefGoogle Scholar
Wahlén, E. 2009 Steady water waves with a critical layer. J. Differ. Equ. 246, 24682483.CrossRefGoogle Scholar

Flamarion et al. supplementary movie 1

Evolution of the Kelvin cat-eye structure due to an initial wave disturbance propagating towards the bottom topography.

Download Flamarion et al. supplementary movie 1(Video)
Video 4 MB

Flamarion et al. supplementary movie 2

Onset and evolution of the Kelvin cat-eye structure due to wave generation by a current-topography interaction.

Download Flamarion et al. supplementary movie 2(Video)
Video 6.2 MB

Flamarion et al. supplementary movie 3

Onset and evolution of the Kelvin cat-eye structure due to wave generation by a surface pressure distribution.

Download Flamarion et al. supplementary movie 3(Video)
Video 1.5 MB