Nonlinear resonance in barotropic-baroclinic transfer generated by bottom sills

Julia Boschan, Miklós Vincze, Imre M. Jánosi, Tamás Tél

Research output: Article

5 Citations (Scopus)

Abstract

Internal waves generated by surface perturbations are studied in a two-layer fluid in the presence of two thin sills of equal height in the lower layer, both experimentally and numerically. Small amplitude surface waves are found to generate internal waves of large amplitude at the density interface in between the two sills. The largest amplitude internal waves appear if a resonance condition is fulfilled: if half of the wavelength of the internal wave of the period of the external perturbation fits into the distance between the two sills in the form of standing waves. The internal waves are then apparently nonlinear, nevertheless, the predictions of a linear theory for the resonance condition apply by taking into account a systematic change in the wavelength caused by nonlinearity, and the deviation from a sharp density interface. Interestingly, the shape of these internal waves is found to be nearly sinusoidal. A precise classification proves them to be cnoidal waves with a small elliptic parameter m.

Original languageEnglish
Article number046601
JournalPhysics of Fluids
Volume24
Issue number4
DOIs
Publication statusPublished - ápr. 2 2012

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ASJC Scopus subject areas

  • Computational Mechanics
  • Condensed Matter Physics
  • Mechanics of Materials
  • Mechanical Engineering
  • Fluid Flow and Transfer Processes

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