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Article
Evaluation of Mean Velocity and Turbulence Measurements with ADCPs
Journal of Hydraulic Engineering
  • Elizabeth A. Nystrom, United States Geological Survey
  • Chris R. Rehmann, Iowa State University
  • Kevin A. Oberg, United States Geological Survey
Document Type
Article
Publication Version
Published Version
Publication Date
1-1-2007
DOI
10.1061/(ASCE)0733-9429(2007)133:12(1310)
Abstract

To test the ability of acoustic Doppler current profilers (ADCPs) to measure turbulence, profiles measured with two pulse-to-pulse coherent ADCPs in a laboratory flume were compared to profiles measured with an acoustic Doppler velocimeter, and time series measured in the acoustic beam of the ADCPs were examined. A four-beam ADCP was used at a downstream station, while a three-beam ADCP was used at a downstream station and an upstream station. At the downstream station, where the turbulence intensity was low, both ADCPs reproduced the mean velocity profile well away from the flume boundaries; errors near the boundaries were due to transducer ringing, flow disturbance, and sidelobe interference. At the upstream station, where the turbulence intensity was higher, errors in the mean velocity were large. The four-beam ADCP measured the Reynolds stress profile accurately away from the bottom boundary, and these measurements can be used to estimate shear velocity. Estimates of Reynolds stress with a three-beam ADCP and turbulent kinetic energy with both ADCPs cannot be computed without further assumptions, and they are affected by flow inhomogeneity. Neither ADCP measured integral time scales to within 60%.

Comments

This is an article from Journal of Hydraulic Engineering 133 (2007), doi:10.1061/(ASCE)0733-9429(2007)133:12(1310).

Rights
Works produced by employees of the U.S. Government as part of their official duties are not copyrighted within the U.S. The content of this document is not copyrighted.
Language
en
File Format
application/pdf
Citation Information
Elizabeth A. Nystrom, Chris R. Rehmann and Kevin A. Oberg. "Evaluation of Mean Velocity and Turbulence Measurements with ADCPs" Journal of Hydraulic Engineering Vol. 133 Iss. 12 (2007) p. 1310 - 1318
Available at: http://works.bepress.com/chris_rehmann/19/