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The energy decay in self-preserving isotropic turbulence revisitedThe assumption of self-preservation allows for an analytical determination of the energy decay in isotropic turbulence. Here, the self-preserving isotropic decay problem is analyzed, yielding a more complete picture of self-serving isotropic turbulence. It is proven rigorously that complete self-serving isotropic turbulence admits two general types of asymptotic solutions: one where the turbulent kinetic energy K approximately t (exp -1) and one where K approximately t (sup alpha) with an exponent alpha greater than 1 that is determined explicitly by the initial conditions. By a fixed point analysis and numerical integration of the exact one-point equations, it is demonstrated that the K approximately t (exp -1) and where K approximately t (sup -alpha) with an exponent alpha greater than 1 that is determined explicitly by the initial conditions. By a fixed point analysis and numerical integration of the exact one-point equations, it is demonstrated that the K approximately t (exp -1) power law decay is the asymptotically consistent high Reynolds number solution; the K approximately 1 (sup -alpha) decay law is only achieved in the limit as t yields infinity and the turbulence Reynolds number vanishes. Arguments are provided which indicate that a K approximately t (exp -1) power law decay is the asymptotic state toward which a complete self-preserving isotropic turbulence is driven at high Reynolds numbers in order to resolve the imbalance between vortex stretching and viscous diffusion.
Document ID
19920071866
Acquisition Source
Legacy CDMS
Document Type
Reprint (Version printed in journal)
Authors
Speziale, Charles G.
(NASA Langley Research Center Hampton, VA, United States)
Bernard, Peter S.
(Maryland, University College Park, United States)
Date Acquired
August 15, 2013
Publication Date
August 1, 1992
Publication Information
Publication: Journal of Fluid Mechanics
Volume: 241
ISSN: 0022-1120
Subject Category
Fluid Mechanics And Heat Transfer
Accession Number
92A54490
Funding Number(s)
CONTRACT_GRANT: NAS1-18605
Distribution Limits
Public
Copyright
Other

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