Occurrence Frequency of Air-flow Separation over Wind Waves

• MIZUTANI Natsuki

  Osaka Sangyo University

• Edwin A. Cowen

  Cornell University

• MIYAJIMA Masahiro

  Osaka Sangyo University

Bibliographic Information

Other Title

• 風波上の気流の剥離の発生頻度とその要因について

Abstract

We carried out the visualization experiment on air-flows over wind waves to investigate an occurrence frequency of an air-flow separation behind a wind wave crest. An air-flow separation behind a wave crest strongly depends on a local wave shape around the wave crest, but the occurrence frequency of the air-flow separation can be explained by the wave steepness. Physical surface roughness (significant wave height) grows as wind speed increases. However, the surface roughness length, z0, doesn't grow. If the air-flow separation occurs over wind waves, the air-flow travels from the wave crest to the next wave crest. Then, the air-flow doesn't sense as physical surface roughness as significant wave height. Therefore, the surface roughness length doesn't grow as wind speed increases.

Journal

• Journal of Japan Society of Civil Engineers, Ser. B2 (Coastal Engineering)

  Journal of Japan Society of Civil Engineers, Ser. B2 (Coastal Engineering) 65 (1), 76-80, 2009

  Japan Society of Civil Engineers

Keywords

• wind wave
• air-flow separation
• momentum transfer
• roughness length

Details

• CRID: 1390282680294744192
• NII Article ID: 130004956193
• DOI: 10.2208/kaigan.65.76
• ISSN: 18838944
• ISSN: 18842399
• Text Lang: en
• Data Source:
  • JaLC
  • Crossref
  • CiNii Articles
• Abstract License Flag: Disallowed