Weir velocity formulation for sharp-crested rectangular weirs

Date

2015-03-01

Author

GHARAHJEH, Siamak
Aydın, İsmail
Altan Sakarya, Ayşe Burcu

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Discharge in open channels can be measured by sharp-crested rectangular weirs. Generally, measured head over the weir crest is substituted into an empirical formula derived from energy considerations to calculate the discharge. Assumptions made on the derivation are taken into account by defining a discharge coefficient that fits into the experimental data. In this study, a physical quantity, the average velocity over the weir section defined as 'weir velocity' is directly formulated as function of weir geometry and head over the weir. Weir velocity plotted against the weir head has a universal behavior for constant weir width to channel width ratio independent of the weir size. This unique behavior is described in terms of weir parameters to calculate the discharge without involving a discharge coefficient. Combining weir velocity data for variable weir widths provides a basis for direct formulation of discharge. The weir velocity exhibits simpler functional dependency on weir parameters in contrast to the discharge coefficient.

Subject Keywords

Flow Measurement, Discharge, Sharp-Crested Weirs, Rectangular Weir, Open-Channel Flow

URI

https://hdl.handle.net/11511/36682

Journal

FLOW MEASUREMENT AND INSTRUMENTATION

DOI

https://doi.org/10.1016/j.flowmeasinst.2014.10.018

Collections

Department of Civil Engineering, Article

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Citation Formats

S. GHARAHJEH, İ. Aydın, and A. B. Altan Sakarya, “Weir velocity formulation for sharp-crested rectangular weirs,” FLOW MEASUREMENT AND INSTRUMENTATION, pp. 50–56, 2015, Accessed: 00, 2020. [Online]. Available: https://hdl.handle.net/11511/36682.