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The orientation of helical flow in curved channels
Author(s) -
CORNEY RANSOME K. T.,
PEAKALL JEFFREY,
PARSONS DANIEL R.,
ELLIOTT LIONEL,
AMOS KATHRYN J.,
BEST JAMES L.,
KEEVIL GARETH M.,
INGHAM DEREK B.
Publication year - 2006
Publication title -
sedimentology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.494
H-Index - 108
eISSN - 1365-3091
pISSN - 0037-0746
DOI - 10.1111/j.1365-3091.2006.00771.x
Subject(s) - geology , subaerial , fluvial , submarine , flow (mathematics) , channel (broadcasting) , meander (mathematics) , geometry , orientation (vector space) , flow velocity , open channel flow , bed load , mechanics , sediment transport , geomorphology , sediment , physics , paleontology , engineering , oceanography , mathematics , structural basin , electrical engineering
The planform patterns of meandering submarine channels and subaerial fluvial bends show many similarities that have given rise to strong analogies concerning the fluid dynamics of these channel types. Existing models of helical motion in open‐channel bends depict flow that is characterized by surface flow towards the outer bank, and basal flow towards the inner bank. This paper investigates and compares, through an analytical model and physical experiment, flows within fluvial meanders, and submarine channel bends that contain density‐driven gravity currents. The results indicate that the sense of helical motion can be reversed in submarine bends that contain density currents when compared with fluvial bends, and that the orientation of the helical flow is dependent on the vertical distribution of downstream velocity. Specifically, the sense of helical motion is reversed in bends when the maximum downstream velocity is near the bed, resulting in near‐bed flow towards the outer bank. These findings suggest that the dynamics of sediment transport and deposition in curved channels with such velocity profiles will be fundamentally different to those currently assumed from sinuous open‐channels.