View in EDS

Rating Rectangular Farm Delivery Meter Gates for Flow Measurement.

Saved in:
Bibliographic Details
Title: Rating Rectangular Farm Delivery Meter Gates for Flow Measurement.
Authors: Howes, Daniel J.1 djhowes@calpoly.edu, Burt, Charles M.2 cburt@calpoly.edu
Source: Journal of Irrigation & Drainage Engineering. Jan2016, Vol. 142 Issue 1, p1-8. 8p.
Subjects: Hydraulic gates, Flow measurement, Measurement uncertainty (Statistics), Irrigation, Canals, Open-channel flow
Geographic Terms: California
Abstract: Traditional meter gates for farm delivery flow measurement from an open channel conveyance have traditionally incorporated round canal gates (Armco type) for control. In recent years, some irrigation water agencies (i.e., irrigation districts) have replaced deteriorating round gates with lower-cost rectangular gates that cover round holes. Similar to the situation described in a companion paper, where round gates were examined, there have been no investigations into flow measurement uncertainty using the existing rating tables for these gates. In this study, two commonly used rectangular gate sizes, 0.46 m (18-in.) and 0.61 m (24-in.), were tested under scenarios of various gate openings, upstream heads, and head differences. Coefficient of discharge (Cd) values were computed based on actual gate open areas. These improved Cd values were used to generate new discharge rating tables for 0.46 m (18-in.) and 0.61 m (24-in.) rectangular meter gates. Limitations for these rectangular gates are discussed. If guidelines presented in this paper and in the companion paper are followed, the average instantaneous flow measurement uncertainty that could be expected is better than ±5%. However, uncertainty is higher (up to approximately ±9.5%) at the lower end of the recommended gate openings [0.10 m (4 in.)] for these rectangular gates. [ABSTRACT FROM AUTHOR]
Copyright of Journal of Irrigation & Drainage Engineering is the property of American Society of Civil Engineers and its content may not be copied or emailed to multiple sites without the copyright holder's express written permission. Additionally, content may not be used with any artificial intelligence tools or machine learning technologies. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)
Database: Engineering Source
Description
Abstract:Traditional meter gates for farm delivery flow measurement from an open channel conveyance have traditionally incorporated round canal gates (Armco type) for control. In recent years, some irrigation water agencies (i.e., irrigation districts) have replaced deteriorating round gates with lower-cost rectangular gates that cover round holes. Similar to the situation described in a companion paper, where round gates were examined, there have been no investigations into flow measurement uncertainty using the existing rating tables for these gates. In this study, two commonly used rectangular gate sizes, 0.46 m (18-in.) and 0.61 m (24-in.), were tested under scenarios of various gate openings, upstream heads, and head differences. Coefficient of discharge (Cd) values were computed based on actual gate open areas. These improved Cd values were used to generate new discharge rating tables for 0.46 m (18-in.) and 0.61 m (24-in.) rectangular meter gates. Limitations for these rectangular gates are discussed. If guidelines presented in this paper and in the companion paper are followed, the average instantaneous flow measurement uncertainty that could be expected is better than ±5%. However, uncertainty is higher (up to approximately ±9.5%) at the lower end of the recommended gate openings [0.10 m (4 in.)] for these rectangular gates. [ABSTRACT FROM AUTHOR]
ISSN:07339437
DOI:10.1061/(ASCE)IR.1943-4774.0000931