Comparison Between Triangular Cylinder and Screen Near-Wakes in the Orthogonal Wavelet Representation

• LI Hui

  Department of Mechanical Systems Engineering, Faculty of Engineering, Yamagata University

• ZHOU Yu

  Department of Mechanical Engineering, The Hong Kong Polytechnic University

抄録

The near wake generated by a triangular cylinder and a screen, respectively, has been investigated with a view to provide information on the effect of initial conditions on turbulence structures of various scales based on the wavelet multi-resolution analysis. The velocity data were simultaneously obtained at x/h (x is the streamwise distance downstream of the wake generator and h is the height of the wake generator)=20 using a rake of eight X-wires aligned in the plane of mean shear. A vector wavelet multi-resolution technique was applied to decompose the velocity data into a number of wavelet components based on the central frequencies. The instantaneous sectional streamlines and vorticity field were used to reveal the turbulent structures at each wavelet component/central frequency. It was found that the behavior of large- and intermediate-scale structures depend on the initial conditions and the small-scale structures are independent of the initial conditions. The contributions from the wavelet components to the time-averaged Reynolds stresses and vorticity variance were estimated. Both the large-scale and intermediate longitudinal structures make the most significant contributions to Reynolds stresses in the triangular cylinder wake, but the contribution from the large-scale structures appears dominating in the screen wake. The relatively small-scale structures of the triangular cylinder wake contribute most to the total spanwise vorticity variance.

収録刊行物

• JSME International Journal Series B Fluids and Thermal Engineering

  JSME International Journal Series B Fluids and Thermal Engineering 46 (3), 366-376, 2003

  一般社団法人 日本機械学会

キーワード

• Flow Measurements
• Initial Conditions
• Multi-Scale Flow Structures
• Orthogonal Wavelet Transform
• Turbulence
• Near Wake
• Vector Wavelet Multi-Resolution Analysis
• Vortex

詳細情報

• CRID: 1390282679652711040
• NII論文ID: 110003479164
• NII書誌ID: AA10888815
• DOI: 10.1299/jsmeb.46.366
• ISSN: 13475371
• ISSN: 13408054
• NDL書誌ID: 6640274
• Web Site: https://ndlsearch.ndl.go.jp/books/R000000004-I6640274
• Web Site: http://www.jstage.jst.go.jp/article/jsmeb/46/3/46_3_366/_pdf
• 本文言語コード: en
• データソース種別:
  • JaLC
  • NDL
  • Crossref
  • CiNii Articles
• 抄録ライセンスフラグ: 使用不可