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Influence of a mean shear on the spectrum of passive scalar fluctuations
Author(s) -
Celani A.,
Cencini M.,
Vergassola M.,
Villermaux E.,
Vincenzi D.
Publication year - 2007
Publication title -
pamm
Language(s) - English
Resource type - Journals
ISSN - 1617-7061
DOI - 10.1002/pamm.200700285
Subject(s) - scalar (mathematics) , shear (geology) , turbulence , inertial frame of reference , wavenumber , fluctuation spectrum , physics , spectrum (functional analysis) , mechanics , classical mechanics , mathematics , materials science , condensed matter physics , quantum mechanics , geometry , composite material
The form of the spectrum of passive scalar fluctuations in the inertial–convective range is investigated. In the presence of a mean shear, there exists a critical wave number k c . At wave numbers greater than k c , the mean shear does not influence the spectrum of scalar fluctuations and the Obukhov–Corrsin prediction holds. At wave numbers smaller than k c , the mean shear dominates and the spectrum is less steep. These predictions are based on the study of Lagrangian dynamics of fluid particles and account for the experimental observations. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)