Hierarchical vortical structures extracted from turbulent fields

M. Hirota, Y. Nishio, S. Izawa, Y. Fukunishi

Research output: Contribution to journalArticle

Abstract

Geometrical relationships and interactions among hierarchical structures in isotropic turbulence are investigated by identifying individual vortices of three different scales in the inertial subrange. Fourier bandpass filters are employed to extract the vortices, and each extracted vortex is replaced by a group of vortex segments with a cylindrical shape. The axes of neighboring vortices tend to be anti-parallel when the distance between them is equivalent to their diameter. Further, results indicate that a vortex is most strongly stretched by vortices twice the scale irrespective of the Reynolds number and the vortex scales. Then, the geometric relationships between the vortices being stretched and those that cause the stretching are analyzed, and the stretching is found to be particularly strong when the two vortices are orthogonal to each other.

Original languageEnglish
Article number015503
JournalFluid Dynamics Research
Volume52
Issue number1
DOIs
Publication statusPublished - 2020 Jan 1

Keywords

  • energy cascade
  • Isotropic turbulence
  • vortex stretching

ASJC Scopus subject areas

  • Mechanical Engineering
  • Physics and Astronomy(all)
  • Fluid Flow and Transfer Processes

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