Richardson Pair Dispersion in Two-Dimensional Turbulence
نویسندگان
چکیده
We report the first experimental study of the dispersion of pairs of passive particles, performed in a controlled two-dimensional turbulent flow, in which Kolmogorov-Kraichnan scaling Eskd , k25y3 holds. The Richardson t3 law is observed, and strongly non-Gaussian behavior is obtained for the Lagrangian distributions of separations. The process is shown to be isotropic, and self-similar in time. The observations, which fit well in the Kolmogorov framework, jeopardize the relevance of the Lévy walk approach. [S0031-9007(99)08856-0]
منابع مشابه
Pair dispersion in turbulence
We study the statistics of pair dispersion in two-dimensional turbulence. Direct numerical simulations show that the pdf of pair separations is in agreement with the Richardson prediction. The pdf of doubling times follows dimensional scaling and shows a long tail which is the signature of close approaches between particles initially seeded with a large separation. This phenomenon is related to...
متن کاملPair dispersion over an inertial range spanning many decades
New numerical results on scalar pair dispersion through an inertial range spanning many decades are presented here. These results are achieved through a new Monte Carlo algorithm for synthetic turbulent velocity fields, which has been developed and validated recently by the authors @J. Comput. Phys. 117, 146 ~1995!#; this algorithm is capable of accurate simulation of a Gaussian incompressible ...
متن کاملStatistics of two-particle dispersion in two-dimensional turbulence
We investigate Lagrangian relative dispersion in direct numerical simulation of two-dimensional inverse cascade turbulence. The analysis is performed by using both standard fixed time statistics and an exit time approach. The latter allows a more precise determination of the Richardson constant which is found to be g.4 with a possible weak finite-size dependence. Our results show only small dev...
متن کاملThe dependence of relative dispersion on turbulence scales in Lagrangian Stochastic Models
The aim of the article is to investigate the relative dispersion properties of the Well Mixed class of Lagrangian Stochastic Models. Dimensional analysis shows that given a model in the class, its properties depend solely on a non-dimensional parameter, which measures the relative weight of Lagrangian-to-Eulerian scales. This parameter is formulated in terms of Kolmogorov constants, and model p...
متن کاملPair dispersion in synthetic fully developed turbulence.
The Lagrangian statistics of relative dispersion in fully developed turbulence is numerically investigated. A scaling range spanning many decades is achieved by generating a two-dimensional velocity field by means of a stochastic process with prescribed statistics and of a dynamical model (shell model) with fluctuating characteristic times. When the velocity field obeys Kolmogorov similarity, t...
متن کامل