Passive scalar spectrum in the viscous-convective range in two-dimensional steady turbulence

• Toshiyuki, Gotoh

• Junji, Nagaki

• Yukio, Kaneda

抄録

The spectrum of a passive scalar field in the viscous-convective range convected by two-dimensional steady turbulence was studied using the Lagrangian Renormalized Approximation (LRA) and high resolution DNS with a resolution up to 40962. It was found that the scalar spectrum F(k) using the LRA scales as k-1 in the range, and decays Gaussianly in the far diffusive range, and these wavenumber dependencies in both ranges agree with the DNS data. A new Lagrangian closure approximation that is invariant under random Galilean transformation and random uniform rotation is proposed. The approximation makes better quantitative predictions than the LRA and yields F(k) = CVC(ν/)1/2k-1 with CVC = 5.25 in the viscous-convective range, which is in good agreement with the DNS value CVC = 5.11. The importance of molecular diffusion in the far diffusive range when the viscous-convective range exists is also discussed.

収録刊行物

• PHYSICS OF FLUIDS

  PHYSICS OF FLUIDS 12 (1), 155-168, 2000-01

  American Institute of Physics

キーワード

• Condensed Matter Physics
• Fluid Flow and Transfer Processes
• Mechanics of Materials
• Computational Mechanics
• Mechanical Engineering

詳細情報

• CRID: 1050001337492296064
• NII論文ID: 120005975517
• NII書誌ID: AA10986202
• ISSN: 10706631
• ISSN: 10897666
• DOI: 10.1063/1.870291
• Web Site: http://id.nii.ac.jp/1476/00004761/
• Web Site: https://pubs.aip.org/aip/pof/article-pdf/12/1/155/19060421/155_1_online.pdf
• 本文言語コード: en
• 資料種別: journal article
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