Abstract

Basic experiments were conducted in a near full-scale compound sharp-crested weir. The compound sharp-crested weir composed of a trapezoidal weir, sloping crests and a rectangular weir. Detailed velocity measurements were performed for the effects of the compound weir geometry on the flow velocity distributions and the kinetic energy correction factors. Furthermore, a theoretical discharge equation for the proposed compound weir was derived and experimentally validated. The results showed that the kinetic energy correction factors decreased with increasing the head of the weir. The weir behaves as uniform flows passing over the weir under the conditions of the . The proposed compound weir provided a good estimation of the discharge without discontinuities. Consequently, an equation for the discharge coefficient was introduced. The experimental data indicated that the discharge coefficient could be simplified in the form of the relative head .

Key words: Compound sharp-crested weir, velocity distributions, water discharge.