Particle dispersion by random waves in rotating shallow water

Research output: Contribution to journalArticle

Abstract

We present a theoretical and numerical study of wave-induced particle dispersion due to random waves in the rotating shallow-water system, as part of an ongoing study of particle dispersion in the ocean. Specifically, the effective particle diffusivities in the sense of Taylor (Proc. Lond. Math. Soc., vol. 20, 1921, p. 196) are computed for a small-amplitude wave field modelled as a stationary homogeneous isotropic Gaussian random field whose frequency spectrum is bounded away from zero. In this case, the leading-order diffusivity depends crucially on the nonlinear, second-order corrections to the linear velocity field, which can be computed using the methods of wavemean interaction theory. A closed-form analytic expression for the effective diffusivity is derived and carefully tested against numerical Monte Carlo simulations. The main conclusions are that Coriolis forces in shallow water invariably decrease the effective particle diffusivity and that there is a peculiar choking effect for the second-order particle flow in the limit of strong rotation.

Original languageEnglish (US)
Pages (from-to)5-26
Number of pages22
JournalJournal of Fluid Mechanics
Volume638
DOIs
StatePublished - Nov 2009

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shallow water
diffusivity
Water
Coriolis force
oceans
velocity distribution
simulation
interactions

ASJC Scopus subject areas

  • Mechanical Engineering
  • Mechanics of Materials
  • Condensed Matter Physics

Cite this

Particle dispersion by random waves in rotating shallow water. / Buhler, Oliver; Holmes-Cerfon, Miranda.

In: Journal of Fluid Mechanics, Vol. 638, 11.2009, p. 5-26.

Research output: Contribution to journalArticle

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