Discharge coefficient of sharp-crested weirs using potential flow

Abstract

Sharp-crested weirs are used in hydraulic structures for accurate discharge measurement. Using a plane vertical plate perpendicular to the flowdirection and applying the theory of complex variables, an equation is developed for estimating the discharge coefficient of rectangular sharp-crested weirs by the potential flow theory. The results reveal that the ratio of overflow head to the weir height can be presented by a power equation to obtain a correction factor to determine the discharge coefficient. Experimental data indicate that the suggested equation for the discharge coefficient gives reasonable results for a large range of relative overflow depths.

Keywords:

• Discharge coefficient
• Flow measurement
• Potential flow
• Power equation
• Sharp-crested weir