Enhancement of Heat Transfer and Reduction of Drag of a Circular Cylinder. Flow Control Using a Small Rod.

• TSUTSUI Takayuki

• IGARASHI Tamotsu

Bibliographic Information

Other Title

• 円柱に働く抗力の軽減と伝熱促進　小さなロッドによる流れ場の制御
• エンチュウ ニ ハタラク コウリョク ノ ケイゲン ト デンネツ ソクシン チ

Abstract

A small rod was set upstream of a circular cylinder for enhancement of heat transfer and reduction of drag of the circular cylinder. The diameter of the cylinder was 40mm, and that of the rod d was varied from 1 to 12 mm. The distance between the axes of the cylinder and rod L was varied from 50 to 120mm, and Reynolds number ranged from 1.5×10⁴ to 6.2×10⁴. The local heat transfer distribution has a maximum at the angle of ±30∼35°from the front stagnation point, regardless of the presence or absence of vortex shedding from the rod. Therefore, the heat transfer at the front face increases markedly. Beyond R_e≥3.1×10⁴, a second maximum of heat transfer appears at φ=±11O°upon transition to turbulent flow. In the separated region at the rear face, the heat transfer decreases. The overall heat transfer increases with an increase in d/D and a decrease in L/D. This method is useful for higher Reynolds numbers. The optimum conditions are d/D=0.25 and L/D=1.25, that is, the case in which quasi-stationary vortices are formed between the rod and the cylinder. In this case, the overall heat transfer increases by 40%, and the total drag coefficient included the drag of the rod is reduced by 43% compared to that of without the rod.

Journal

• TRANSACTIONS OF THE JAPAN SOCIETY OF MECHANICAL ENGINEERS Series B

  TRANSACTIONS OF THE JAPAN SOCIETY OF MECHANICAL ENGINEERS Series B 62 (597), 1802-1809, 1996

  The Japan Society of Mechanical Engineers

Keywords

• Flow Visualization

Details

• CRID: 1390282680872774400
• NII Article ID: 110002394866
• NII Article ID: 130004222171
• NII Book ID: AN00187441
• DOI: 10.1299/kikaib.62.1802
• ISSN: 18848346
• ISSN: 03875016
• ISSN: http://id.crossref.org/issn/00256501
• NDL BIB ID: 3965911
• Web Site: https://ndlsearch.ndl.go.jp/books/R000000004-I3965911
• Web Site: http://www.jstage.jst.go.jp/article/kikaib1979/62/597/62_597_1802/_pdf
• Text Lang: ja
• Data Source:
  • JaLC
  • NDL
  • Crossref
  • CiNii Articles
• Abstract License Flag: Disallowed