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Evaluation of mean velocity and turbulence measurements with ADCPs

Journal of Hydraulic Engineering

By:
, , and
DOI: 10.1061/(ASCE)0733-9429(2007)133:12(1310)

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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%. ?? 2007 ASCE.

Additional Publication Details

Publication type:
Article
Publication Subtype:
Journal Article
Title:
Evaluation of mean velocity and turbulence measurements with ADCPs
Series title:
Journal of Hydraulic Engineering
DOI:
10.1061/(ASCE)0733-9429(2007)133:12(1310)
Volume
133
Issue:
12
Year Published:
2007
Language:
English
Larger Work Type:
Article
Larger Work Subtype:
Journal Article
Larger Work Title:
Journal of Hydraulic Engineering
First page:
1310
Last page:
1318
Number of Pages:
9