Extraction of coherent vortices from homogeneous turbulence using curvelets and total variation filtering methods

Tamer Nabil, Waleed Abdel Kareem, Seiichiro Izawa, Yu Fukunishi

Research output: Contribution to journalArticlepeer-review

12 Citations (Scopus)

Abstract

Most filtering methods for turbulent flow depend on wavelet and Fourier decompositions; however, this paper employs curvelets and total variation (TV) filtering methods. These two methods are investigated to extract the coherent and incoherent parts of a forced homogeneous isotropic turbulent field. The Lattice Boltzmann method with resolutions of 128 3 and 256 3 is used to simulate the turbulent fields, and the Q-identification method is applied to extract the elongated vortical structures. Most of the previous efforts apply filtering techniques to the velocity or vorticity fields; however, this paper applies the two filtering methods to the Q-field. 3D curvelet filtering is applied using a nonlinear thresholding technique. The 3D total variation method is applied using the split Bregman regularization method. The results indicate that the two filtering methods identify the coherent and incoherent parts smoothly. The results of the two filtering methods tend to identify coherent vortices and remove incoherent noise without any change in the physical structure of the turbulent fields. The results are compared with previous efforts using wavelet and Fourier decompositions.

Original languageEnglish
Pages (from-to)76-86
Number of pages11
JournalComputers and Fluids
Volume57
DOIs
Publication statusPublished - 2012 Mar 30

Keywords

  • 3D curvelet transform
  • Coherent and incoherent flows
  • Lattice Boltzmann
  • Split Bregman method
  • Total variation

ASJC Scopus subject areas

  • Computer Science(all)
  • Engineering(all)

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