Lateral Weirs in Trapezoidal Channels

Abstract

The theory of lateral flow through a two‐dimensional channel outlet is used to derive an expression for the outflow through a trapezoidal lateral weir discharging from a trapezoidal channel. The analysis is an extension of the existing hydrodynamic model for lateral flow through a rectangular weir located in the side of a rectangular channel. The weir discharge coefficient is expressed as a function of a parameter relating the geometry of the weir and the channel and a parameter denoting the ratio of the mean velocity of the channel to the resultant jet velocity of the weir flow. Experimental results are provided to validate the proposed expressions for the weir discharge coefficient.