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Agricultural and Resource Economics Commons™
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Full-Text Articles in Agricultural and Resource Economics
Velocity Contour Weighting Method. I: Algorithm Development And Laboratory Testing, Daniel J. Howes, Brett F. Sanders
Velocity Contour Weighting Method. I: Algorithm Development And Laboratory Testing, Daniel J. Howes, Brett F. Sanders
BioResource and Agricultural Engineering
An algorithm is developed for real-time estimation of the cross-sectional average velocity of a channel flow by using an upward-looking pulsed wave acoustic Doppler velocity meters (ADVM). The Velocity Contour Weighting Method (VCWM) is applicable to gradually varied flows in prismatic channels and requires little to no calibration. VCWM estimates the average velocity as a weighted average of ADVM bin velocities. Weights are based on the velocity distribution sampled by the ADVM. Collectively, the VCWM is able to adapt to a wide range of channel geometry and roughness features. Expressions for the velocity weights are developed by first applying a …
Subcritical Contraction For Improved Open-Channel Flow Measurement Accuracy With An Upward-Looking Advm, Daniel Howes, Charles M. Burt, Brett F. Sanders
Subcritical Contraction For Improved Open-Channel Flow Measurement Accuracy With An Upward-Looking Advm, Daniel Howes, Charles M. Burt, Brett F. Sanders
BioResource and Agricultural Engineering
Acoustic Doppler velocity meters (ADVMs) provide an alternative to more traditional flow measurement devices and procedures such as flumes, weirs, and stage rating for irrigation and drainage canals. However, the requirements for correct calibration are extensive and complex. A three-dimensional computational fluid dynamics (CFD) model was used to design a subcritical rapidly varied flow contraction that provides a consistent linear relationship between the upward-looking ADVM sample velocity and the cross-sectional average velocity in order to improve ADVM accuracy without the need for in situ calibration. CFD simulations validated the subcritical contraction in a rectangular and trapezoidal cross section by showing …