图书馆订阅: Guest
TSFP DL Home 旧刊 执委

CVS FILTERING OF TURBULENT MIXING LAYERS USING ORTHOGONAL WAVELET DECOMPOSITION

Kai Schneider
Laboratoire de Modélisation et Simulation Numérique en Mécanique, CNRS et Universités d'Aix-Marseille & CMI, Université de Provence, 39 rue Frédéric Joliot-Curie, 13453 Marseille, France

Marie Farge
LMD-IPSL-CNRS Ecole Normale Superieure 24 rue Lhomond, 75231 Paris Cedex 5, France

Giulio Pellegrino
ICT, Universitat Karlsruhe (TH) Kaiserstr. 12, 76128 Karlsruhe, Germany; Laboratoire de Modélisation et Simulation Numérique en Méecanique du CNRS IMT - Technopole de Chateau-Gombert 38 rue F. Joliot-Curie, 13541 Marseille Cedex 20, France

Michael M. Rogers
Center for Turbulence Research, NASA/Ames Research Center, CA 94035-1000, USA

Abstract

In the present paper we apply the Coherent Vortex Simulation (CVS) filtering to a turbulent mixing layer computed by high resolution Direct Numerical Simulation (DNS). The CVS filtering is based on an orthogonal wavelet decomposition of the vorticity field and a nonlinear thresholding of the wavelet coefficients. The threshold is motivated from optimal denoising theory and only depends on the enstrophy and on the Reynolds number. The presented results show that the coherent part corresponding to the strong wavelet coefficients contains the vortex tubes which reproduce the vorticity PDF and the energy spectrum over the entire inertial range. The remaining incoherent background flow is homogeneous, structurelss, has small amplitude, and is uncorrelated.