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Turbulent stresses and secondary currents in a tidal-forced channel with significant curvature and asymmetric bed forms

Journal of Hydraulic Engineering

By:
, , ,
DOI: 10.1061/(ASCE)0733-9429(2009)135:3(

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Abstract

Acoustic Doppler current profilers are deployed to measure both the mean flow and turbulent properties in a channel with significant curvature. Direct measurements of the Reynolds stress show a significant asymmetry over the tidal cycle where stresses are enhanced during the flood tide and less prominent over the ebb tide. This asymmetry is corroborated by logarithmic fits using 10 min averaged velocity data. A smaller yet similar tendency asymmetry in drag coefficient is inferred by fitting the velocity and estimated large-scale pressure gradient to a one-dimensional along-channel momentum balance. This smaller asymmetry is consistent with recent modeling work simulating regional flows in the vicinity of the study site. The asymmetry in drag suggests the importance of previously reported bed forms for this channel and demonstrates spatial and temporarily variations in bed stress. Secondary circulation patterns observed in a relatively straight section of channel appear driven by local curvature rather than being remotely forced by the regions of significant curvature only a few hundred meters from the measurement site. ?? 2009 ASCE.

Additional Publication Details

Publication type:
Article
Publication Subtype:
Journal Article
Title:
Turbulent stresses and secondary currents in a tidal-forced channel with significant curvature and asymmetric bed forms
Series title:
Journal of Hydraulic Engineering
DOI:
10.1061/(ASCE)0733-9429(2009)135:3(
Volume
135
Issue:
3
Year Published:
2009
Language:
English
Larger Work Type:
Article
Larger Work Subtype:
Journal Article
First page:
198
Last page:
208
Number of Pages:
11