Please use this identifier to cite or link to this item: http://hdl.handle.net/1959.13/925264

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Title
Spectrum of a passive scalar in moderate Reynolds number homogenous isotropic turbulence
Author/Creator
Danaila, L.;  Antonia, R. A.
Institution
The University of Newcastle. Faculty of Engineering & Built Environment, School of Engineering
Description
For moderate Reynolds numbers, the spectral scaling exponents of both velocity [E(k)∞k−mu] and the transported passive scalar [Eθ(k)∞k−mθ] fields exhibit departures from the asymptotic prediction mu = mθ = 5/3. However, at the same Reynolds number, the passive scalar spectrum for homogeneous isotropic turbulence is closer to the universal asymptotic state than the dynamic velocity field that transports it. This paper provides a possible explanation for this behavior, in the case of a gaseous mixing with Prandtl (or Schmidt) number Pr ≃ 1. A scenario of the scalar energy transfer toward higher wavenumbers is proposed and validated using experimental data, in which the velocity field itself is actively involved via its characteristic time. A direct relationship between velocity and scalar spectra and therefore between mu and mθ is thus established.
Relation
Physics of Fluids Vol. 21, Issue 11
Publisher Link
http://dx.doi.org/10.1063/1.3264881
Date
2009
Publisher
American Institute of Physics
Keyword(s)
gas mixtures;  turbulence;  homogenous isotropic turbulence;  Reynolds numbers
Resource Type
journal article
Identifier
http://hdl.handle.net/1959.13/925264
Identifier
ISSN:1070-6631
Reviewed
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Subject
"Physics of Fluids"
 
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