Unsteady Flows Past a Circular Cylinder Started Impulsively in the Reynolds Number Range 500<Re<10<SUP>4</SUP> (The Structure of the Vortex Region and Feeding Mechanism of Vorticity)

• NAGATA Hiroshi

• NAGASE Isao

• ITO Koichi

抄録

Developments of vortices behind a circular cylinder with its impulsive start were investigated by flow visualization techniques. Special attention was paid to elucidating the relation between the structure of vortices and the Reynolds number Re from the viewpoint of the convection of the vorticity generated on the surface of the cylinder. The structure of the vortices varies considerably with the Reynolds number immediately after the start of the cylinder for the duration τ<1∼1.5, where τ is the nondimensional elapsed time .For a high Reynolds number, the separated shear layers roll up close to the separation points and form intense vortices near the rear surface of the cylinder. For Re>3000, the separated vortices induce not only secondary vortices but also tertiary vortices near the separation points. After a duration of τ>1.5, the variation of the structure of the vortices with Re was found to be small. The ratio of the circulation to the area of vortex region has a nearly constant value.

収録刊行物

• JSME international journal. Ser. 2, Fluids engineering, heat transfer, power, combustion, thermophysical properties

  JSME international journal. Ser. 2, Fluids engineering, heat transfer, power, combustion, thermophysical properties 32 (4), 540-549, 1989

  一般社団法人 日本機械学会

キーワード

• Unsteady Flow
• Separation
• Vortex
• Circulation
• Flow Visualization
• Vorticity

詳細情報

• CRID: 1390282680403408512
• NII論文ID: 110002494296
• NII書誌ID: AA10680596
• DOI: 10.1299/jsmeb1988.32.4_540
• ISSN: 09148817
• Web Site: https://www.jstage.jst.go.jp/article/jsmeb1988/32/4/32_4_540/_pdf
• 本文言語コード: en
• データソース種別:
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  • Crossref
  • CiNii Articles
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