侵食性河床におけるステップ発生の線形安定性理論

• 山口 里実

  東北大学大学院工学研究科土木工学専攻

• 泉 典洋

  WEM/SCE, Asian Institute of Technology

書誌事項

タイトル別名

• LINEAR STABILITY ANALYSIS OF STEP INCEPTION ON EROSIONAL BEDS

抄録

The bed form of steep channels are often characterized by a series of steps. In this paper, in order to investigate the mechanism of the inception of steps, a linear stability analysis is performed with the use of the two-dimensional Reynolds equations and the Exner equation for bed erosion. The analysis reveals that the flat bed becomes unstable resulting in the growth of sinusoidal perturbations when the Froude number is larger than 0.6-0.9 and the wavenumber is smaller than 0.7-1.0. The characteristic wavenumber of inceptive steps are in the order of 0.1-1, corresponding to a wavelength of 6-60 times the flow depth. The comparison between the predicted wavenumbers in this analysis and the measurements in Sawai's experiments shows a reasonably good agreement. The analysis can also explain that the steps migrate upstream, which agrees with the observational results.

収録刊行物

• 水工学論文集

  水工学論文集 45 751-756, 2001

  公益社団法人 土木学会

キーワード

• linear stability analysis
• perturbation technique erosional
• bed
• step formation
• characteristic wavelength

詳細情報

• CRID: 1390282680147533952
• NII論文ID: 130003841728
• DOI: 10.2208/prohe.45.751
• ISSN: 18849172
• ISSN: 09167374
• 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