Two-particle dispersion in model two-dimensional velocity fields
Universität Freiburg, Hermann-Herder-Str. 3,
79104 Freiburg, Germany
Corresponding author: a firstname.lastname@example.org
Published online: 15 August 2001
We consider two-particle dispersion in a velocity field, where the relative two-point velocity scales according to and the corresponding correlation time scales as , and fix , as typical for turbulent flows. We show that two generic types of dispersion behavior arize: For the correlations in relative velocities decouple and the diffusion approximation holds. In the opposite case, the relative motion is strongly correlated. The case of Kolmogorov flows corresponds to a marginal, nongeneric situation. In this case, depending on the particular parameters of the flow, the dispersion behavior can be rather diffusive or rather ballistic.
PACS: 05.40.-a – Fluctuation phenomena, random processes, noise, and Brownian motion / 47.27.Qb – Turbulent diffusion
© EDP Sciences, Società Italiana di Fisica, Springer-Verlag, 2001