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CVS Decomposition of 3D Homogeneous Turbulence Using Orthogonal WaveletsThis paper compares the filtering used in Coherent Vortex Simulation (CVS) decomposition with an orthogonal wavelet basis, with the Proper Orthogonal Decomposition (POD) or Fourier filtering. Both methods are applied to a field of Direct Numerical Simulation (DNS) data of 3D forced homogeneous isotropic turbulence at microscale Reynolds number R(sub lambda) = 168. We show that, with only 3%N retained modes, CVS filtering separates the coherent vortex tubes from the incoherent background flow. The latter is structureless, has an equipartition energy spectrum, and has a Gaussian velocity probability distribution function (PDF) and an exponential vorticity PDF. On the other hand, the Fourier basis does not extract the coherent vortex tubes cleanly and leaves organized structures in the residual high wavenumber modes whose PDFs are stretched exponentials for both the velocity and the vorticity.
Document ID
20010021415
Acquisition Source
Ames Research Center
Document Type
Conference Paper
Authors
Farge, Marie
(Ecole Normale Superieure Paris, France)
Schneider, Kai
(Provence Univ. Marseille, France)
Pellegrino, Giulio
(Karlsruhe Univ. Germany)
Wray, A. A.
(NASA Ames Research Center Moffett Field, CA United States)
Rogallo, R. S.
(NASA Ames Research Center Moffett Field, CA United States)
Date Acquired
August 20, 2013
Publication Date
November 1, 2000
Publication Information
Publication: Studying Turbulence Using Numerical Simulation Databases, 8. Proceedings of the 2000 Summer Program
Subject Category
Fluid Mechanics And Thermodynamics
Distribution Limits
Public
Copyright
Work of the US Gov. Public Use Permitted.
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