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Study on Generation of Periodical Large Surface Eddies in a Composite Channel Flow
Author(s) -
Tamai Nobuyuki,
Asaeda Takashi,
Ikeda Hirokazu
Publication year - 1986
Publication title -
water resources research
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.863
H-Index - 217
eISSN - 1944-7973
pISSN - 0043-1397
DOI - 10.1029/wr022i007p01129
Subject(s) - eddy , vortex , mechanics , flow (mathematics) , channel (broadcasting) , flow visualization , shear (geology) , composite number , geology , materials science , geometry , turbulence , physics , mathematics , engineering , composite material , telecommunications , petrology
A set of comparative experiments are employed to identify a predominant factor in the generation of large eddies on the water surface at the interface between the main channel and the floodplain in a composite channel flow. It is indicated that the large surface eddies are not phenomena whose action resembles boiling but tornadolike vortices generated by the local shear layer at the interface. Flow visualization technique showed that there existed a complicated three‐dimensional structure in the form of inclined vortex tubes which behaved like longitudinal vortices near the top edge of the floodplain as well as periodically generated large surface eddies. The periodicity of those phenomena is explained as the preferred mode of the local shear layer with two‐dimensional stability analysis.