Sloping Crest Crump Weir

Abstract

A hydraulic model study of an existing sloping crest Crump weir is described. Two models of scales 1:10 and 1:3 were tested. At relatively large heads, the structure behaves as one half of a flat‐V Crump weir with the same transverse crest slope. At lower heads, the flow cross section becomes strongly nonsymmetrical with a consequent significant decrease in the value of the discharge coefficient. The critical head at which departure from a constant discharge coefficient commences is sensitive to the extent of upstream sedimentation in the channel. The sloping crest Crump weir should not be used for flow measurement in a straight channel without an associated model study or an extensive field calibration.