Influence of small wavy roughness on flatplate boundary layer natural transition

• TAMEIKE Hiroki

  Institute of Fluid Science, Tohoku University Department of Aerospace Engineering, Tohoku University

• YAKENO Aiko

  Institute of Fluid Science, Tohoku University

• OBAYASHI Shigeru

  Institute of Fluid Science, Tohoku University

抄録

One of the effective ways to reduce viscous drag around an airfoil is by delaying the boundary layer transition. In this study, we analyzed the influence of a small wavy roughness on a two-dimensional, natural boundary layer transition, using direct numerical simulation that resolved each small roughness. A parametric study was conducted on the wavy roughness wavelength. Our results show that in some cases the transition delays whose characteristics depend on the roughness wavelength. In a detailed analysis, we found that the wavy roughness firstly affects the process of primary vortex growth, Tollmien–Schlichting (TS) instability. In addition, we found that the secondary vortex pairing also depended on it. In the most transition-delayed cases, the roughness wavelength was different far from the TS instability one, and the vortex pairing occurred firstly in upstream however not much in downstream, keeping the vortex size is kept small.

収録刊行物

• Journal of Fluid Science and Technology

  Journal of Fluid Science and Technology 16 (1), JFST0008-JFST0008, 2021

  一般社団法人 日本機械学会

キーワード

• Laminarization
• Surface roughness
• Vortex paring
• Direct numerical simulation (DNS)
• Transition

詳細情報

• CRID: 1391131406295319936
• NII論文ID: 130007965472
• DOI: 10.1299/jfst.2021jfst0008
• ISSN: 18805558
• Web Site: https://www.jstage.jst.go.jp/article/jfst/16/1/16_2021jfst0008/_pdf
• 本文言語コード: en
• データソース種別:
  • JaLC
  • Crossref
  • CiNii Articles
  • KAKEN
• 抄録ライセンスフラグ: 使用不可