HKUST Library Institutional Repository Banner

HKUST Institutional Repository >
Mathematics >
MATH Book Chapters >

Please use this identifier to cite or link to this item:
Title: Decaying turbulence in two and three dimensions
Authors: Chasnov, Jeffrey R.
Keywords: Decaying isotropic turbulence
Reynolds numbers
Low wavenumber spectral coefficients
Numerial simulations
Issue Date: 1997
Citation: Advances in DNS / LES, Greyden Press, Columbus, Ohio, 1997.
Abstract: A review of decaying isotropic turbulence in two and three dimensions is presented. In both dimensions, exact results can be obtained by assuming that for small Reynolds numbers the nonlinear convective terms in the equation of motion are negligible. These analytical results obtained from a linear equation demonstrate explicitly that the decay laws depend on the form of the energy spectrum near zero wavenumber. In three dimensions, high Reynolds number decay laws can be obtained by assuming that these laws continue to depend on invariant or near-invariant low wavenumber spectral coefficients but become independent of viscosity. Results of numerical simulations are presented which smoothly connect the asymptotically high and low Reynolds number solutions. In two dimensions however, high Reynolds number solutions can not be as easily obtained since the dominant nonlinear energy cascade is from small-to-large scales so that an assumption such as the invariance or near-invariance of low wavenumber spectral coefficients becomes untenable. However, exact analytical results in two dimensions can be determined at a transitional Reynolds number, below which final period of decay solutions result and above which the turbulence evolves with increasing Reynolds number.
Appears in Collections:MATH Book Chapters

Files in This Item:

File Description SizeFormat
faicdl.pdf522KbAdobe PDFView/Open

All items in this Repository are protected by copyright, with all rights reserved.