Vortex stretching and compression near the turbulent/non-turbulent interface in a planar jet

Tomoaki Watanabe, Yasuhiko Sakai, Kouji Nagata, Yasumasa Ito, Toshiyuki Hayase

研究成果: Review article査読

34 被引用数 (Scopus)

抄録

Vortex stretching and compression, which cause enstrophy production by inviscid processes, are investigated near the turbulent/non-turbulent (T/NT) interface in a planar jet by using a direct numerical simulation (DNS). The enstrophy production is investigated by analysing the relationship among a vorticity vector, strain-rate eigenvectors and strain-rate eigenvalues. The statistics are calculated individually for three different interface orientations. The vorticity near the T/NT interface is oriented in the tangential direction to the interface. The enstrophy production is affected by the interface orientation because the intensity of vortex stretching depends on the interface orientation, and the alignment between the vorticity vector and the strain-rate eigenvectors is confined by the interface. The enstrophy production near the T/NT interface is analysed by considering the motion of turbulent fluid relative to that of the interface. The results show that the alignment between the interface and the strain-rate eigenvectors changes depending on the velocity field near the T/NT interface. When the turbulent fluid moves toward the T/NT interface, the enstrophy is generated by vortex stretching without being greatly affected by vortex compression. In contrast, when the turbulent fluid relatively moves away from the T/NT interface, large enstrophy reduction frequently occurs by vortex compression. Thus, it is shown that the velocity field near the T/NT interface affects the enstrophy production near the interface through the alignment between the vorticity and the strain-rate eigenvectors.

本文言語English
ページ(範囲)754-785
ページ数32
ジャーナルJournal of Fluid Mechanics
758
DOI
出版ステータスPublished - 2014 11 10

ASJC Scopus subject areas

  • 凝縮系物理学
  • 材料力学
  • 機械工学

フィンガープリント

「Vortex stretching and compression near the turbulent/non-turbulent interface in a planar jet」の研究トピックを掘り下げます。これらがまとまってユニークなフィンガープリントを構成します。

引用スタイル