Weir velocity formulation for sharp-crested rectangular weirs

GHARAHJEH S., AYDIN İ., Altan-Sakarya A. B.

FLOW MEASUREMENT AND INSTRUMENTATION, cilt.41, ss.50-56, 2015 (SCI-Expanded) identifier identifier

  • Yayın Türü: Makale / Tam Makale
  • Cilt numarası: 41
  • Basım Tarihi: 2015
  • Doi Numarası: 10.1016/j.flowmeasinst.2014.10.018
  • Dergi Adı: FLOW MEASUREMENT AND INSTRUMENTATION
  • Derginin Tarandığı İndeksler: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Sayfa Sayıları: ss.50-56
  • Anahtar Kelimeler: Flow measurement, Discharge, Sharp-crested weirs, Rectangular weir, Open-channel flow, SLIT WEIR
  • Orta Doğu Teknik Üniversitesi Adresli: Evet

Özet

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. (C) 2014 Elsevier Ltd. All rights reserved.