シリコンオイルによる水平チャネル内気泡流の摩擦抵抗特性

• 大石 義彦

  北海道大学大学院工学研究院エネルギー環境システム部門

• 村井 祐一

  北海道大学大学院工学研究院エネルギー環境システム部門

• 田坂 裕司

  北海道大学大学院工学研究院エネルギー環境システム部門

書誌事項

タイトル別名

• Friction Drag Characteristics in Horizontal Air-Silicone Oil Bubbly Channel Flow
• (2nd report; Temporal Fluctuation Analysis of Wall Shear Stress)
• (第2報　壁面せん断応力の時間変動解析)

抄録

Skin frictional drag of the gas-liquid two-phase flow is investigated using silicone oil as the test fluid in a horizontal channel. In this 2nd report we focus on time-series characteristics of wall shear stress in addition to conventional average-based evaluation of skin friction characteristics. Influence of the bubble injection in both transition and turbulent flow regimes are examined. Wall shear stress fluctuations indicate that the bubble injection produces quasi-random fluctuations that obey Gaussian distribution and eliminates positive spikes on the fluctuations representing sweep events in turbulent flows. This elimination takes primary role on the drag reduction in the present case that the bubble deformations are allowed. A simultaneous measurement of the both wall shear stress and projection void fraction indicates two important things: (1) the void fraction has significant time fluctuations even by continuous bubble injections; (2) there is a time delay between local maxima of the void fraction and local minima of the wall shear stress.

収録刊行物

• 混相流

  混相流 28 (1), 81-89, 2014

  日本混相流学会

キーワード

• Wall shear stress, Statistical analysis, Bubbly flow, Autocorrelation coefficient, Synchronized measurement

詳細情報

• CRID: 1390001204437514880
• NII論文ID: 130004514130
• DOI: 10.3811/jjmf.28.81
• ISSN: 18815790
• ISSN: 09142843
• 本文言語コード: en
• データソース種別:
  • JaLC
  • Crossref
  • CiNii Articles
• 抄録ライセンスフラグ: 使用不可