Journal of Fluid Mechanics



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Scaling of the energy spectra of turbulent channels


JUAN C. DEL ÁLAMO a1, JAVIER JIMÉNEZ a1a2, PAULO ZANDONADE a3 and ROBERT D. MOSER a3
a1 School of Aeronautics, Universidad Politécnica de Madrid, 28040 Madrid, Spain
a2 Centre for Turbulence Research, Stanford University, Stanford, CA 94305, USA
a3 Department of Theoretical and Applied Mechanics, University of Illinois, Urbana, IL 61801, USA

Article author query
del alamo j   [Google Scholar] 
jimenez j   [Google Scholar] 
zandonade p   [Google Scholar] 
moser r   [Google Scholar] 
 

Abstract

The spectra and correlations of the velocity fluctuations in turbulent channels, especially above the buffer layer, are analysed using new direct numerical simulations with friction Reynolds numbers up to Re$_{\tau}\,{=}\,1900$. It is found, and explained, that their scaling is anomalous in several respects, including a square-root behaviour of their width with respect to their length, and a velocity scaling of the largest modes with the centreline velocity $U_c$. It is shown that this implies a logarithmic correction to the $k^{-1}$ energy spectrum, and that it leads to a scaling of the total fluctuation intensities away from the wall which agrees well with the mixed scaling of de Graaff & Eaton (2000) at intermediate Reynolds numbers, but which tends to a pure scaling with $U_c$ at very large ones.

(Received June 26 2003)
(Revised October 27 2003)



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