Reynolds stresses

From Glossary of Meteorology
(Redirected from Turbulence shear stresses)
The mean forces (per unit area) imposed on the mean flow by turbulent fluctuations.
They arise from the nonlinear advection term when the Navier–Stokes equations are Reynolds decomposed and Reynolds averaged. The general form of the Reynolds stress tensor is
ams2001glos-Re40
Kinematically, the velocity correlation -ams2001glos-Rex08 represents the momentum flux in direction ams2001glos-Rex09 across a plane perpendicular to direction ams2001glos-Rex10 or the momentum flux in direction ams2001glos-Rex11 across a plane perpendicular to direction ams2001glos-Rex12. In a turbulent flow, the divergence of the Reynolds stresses are of leading order in the mean momentum budgets. Typically they are several orders of magnitude larger than the viscous stresses. In the boundary layer, the most important Reynolds stresses are the vertical fluxes of horizontal momentum, ams2001glos-Rex13 and ams2001glos-Rex14.


Copyright 2024 American Meteorological Society (AMS). For permission to reuse any portion of this work, please contact [email protected]. Any use of material in this work that is determined to be “fair use” under Section 107 of the U.S. Copyright Act (17 U.S. Code § 107) or that satisfies the conditions specified in Section 108 of the U.S.Copyright Act (17 USC § 108) does not require AMS’s permission. Republication, systematic reproduction, posting in electronic form, such as on a website or in a searchable database, or other uses of this material, except as exempted by the above statement, require written permission or a license from AMS. Additional details are provided in the AMS Copyright Policy statement.