Coherent vorticity extraction in resistive drift-wave turbulence: Comparison of orthogonal wavelets versus proper orthogonal decomposition

Journal Article · Sat Jan 01 00:00:00 EST 2011 · Comptes Rendus Physique

DOI:https://doi.org/10.1016/j.crhy.2010.12.004· OSTI ID:1036201

Futatani, S ^[1]; Bos, W J.T. ^[2]; Del-Castillo-Negrete, Diego B ^[3]; Schneider, Kai ^[4]; Benkadda, S ^[1]; Farge, Marie ^[5]

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1. France-Japan Magnetic Fusion Laboratory, CNRS, France
2. CNRS, Ecole Centrale de Lyon, Universite Claude Bernard Lyon
3. ORNL
4. Universite d'Aix-Marseille
5. Laboratoire de Meteorologie Dynamique-CNRL, Ecole Normale Superieure

We assess two techniques for extracting coherent vortices out of turbulent flows: the wavelet based Coherent Vorticity Extraction (CVE) and the Proper Orthogonal Decomposition (POD). The former decomposes the flow field into an orthogonal wavelet representation and subsequent thresholding of the coefficients allows one to split the flow into organized coherent vortices with non-Gaussian statistics and an incoherent random part which is structureless. POD is based on the singular value decomposition and decomposes the flow into basis functions which are optimal with respect to the retained energy for the ensemble average. Both techniques are applied to direct numerical simulation data of two-dimensional drift-wave turbulence governed by Hasegawa Wakatani equation, considering two limit cases: the quasi-hydrodynamic and the quasi-adiabatic regimes. The results are compared in terms of compression rate, retained energy, retained enstrophy and retained radial flux, together with the enstrophy spectrum and higher order statistics. (c) 2010 Published by Elsevier Masson SAS on behalf of Academie des sciences.

• Research Organization: Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
• Sponsoring Organization: USDOE Office of Science (SC)
• DOE Contract Number: DE-AC05-00OR22725
• OSTI ID: 1036201
• Journal Information: Comptes Rendus Physique, Vol. 12, Issue 2; ISSN 1631-0705
• Country of Publication: United States
• Language: English

Related Subjects

99 GENERAL AND MISCELLANEOUS//MATHEMATICS, COMPUTING, AND INFORMATION SCIENCE
COMPRESSION
SIMULATION
STATISTICS
TURBULENCE
TURBULENT FLOW
VORTICES