Ocean Stirring by Swimming Bodies

Abstract

We consider the stirring of an inviscid fluid caused by the locomotion of bodies through it. The swimmers are approximated by non-interacting cylinders or spheres moving steadily along straight lines. We find the displacement of fluid particles caused by the nearby passage of a swimmer as a function of an impact parameter. We use this to compute the effective diffusion coefficient from the random walk of a fluid particle under the in influence of a distribution of swimming bodies. We compare with the results of simulations. For typical sizes, densities and swimming velocities of krill, the effective diffusivity in this model is five times the thermal diffusivity. However, we estimate that viscosity increases this value by two orders of magnitude.

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Document Details

Document Type
Technical Report
Publication Date
Mar 01, 2010
Accession Number
ADA519658

Entities

People

  • Jean-Luc Thiffeault
  • Stephen Childress

Organizations

  • University of Minnesota

Tags

Communities of Interest

  • Energy and Power Technologies

DTIC Thesaurus Topics

  • Boundary Layer
  • Buoyancy
  • Diffusion
  • Diffusion Coefficient
  • Diffusivity
  • Equations
  • Flow
  • Fluid Dynamics
  • Mathematics
  • Mixing
  • New York
  • Potential Flow
  • Swimming
  • Three Dimensional
  • Trajectories
  • Two Dimensional
  • Viscous Flow

Fields of Study

  • Mathematics

Readers

  • Atmospheric Science / Meteorology, specifically Wind Wave Turbulence.
  • Marine Mammal Biology
  • Statistical inference.