Abstract
An experimental field study of flows over bedforms was conducted on the Missouri River near St. Charles, Missouri. Detailed velocity data were collected under two different flow conditions along bedforms in this sand-bed river. The large river-scale data reflect flow characteristics similar to those of laboratory-scale flows, with flow separation occurring downstream of the bedform crest and flow reattachment on the stoss side of the next downstream bedform. Wave-like responses of the flow to the bedforms were detected, with the velocity decreasing throughout the flow depth over bedform troughs, and the velocity increasing over befform crests. Local and spatially averaged velocity distributions were logarithmic for both datasets. The reach-wise spatially averaged vertical-velocity profile from the standard velocity-defect model was evaluated. The vertically averaged mean flow velocities for the velocity-defect model were within 5% of the measured values and estimated spatially averaged point velocities were within 10% for the upper 90% of the flow depth. The velocity-defect model, neglecting the wake function, was evaluated and found to estimate the vertically averaged mean velocity within 1% of the measured values.
Original language | English (US) |
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Pages (from-to) | 322-333 |
Number of pages | 12 |
Journal | Journal of Hydraulic Research |
Volume | 46 |
Issue number | 3 |
DOIs | |
State | Published - 2008 |
Keywords
- ADCP
- ADV
- Acoustics
- Bedform
- Field investigation
- Sand-bed river
- Velocity profiles
ASJC Scopus subject areas
- Civil and Structural Engineering
- Water Science and Technology