New Solution Method for Water Surface Profile along a Side Weir in a Circular Channel

Abstract

Side weirs are commonly installed along the sides of open channels. Computation of water surface depth over side weirs is essential to determine their discharge. Analytical solutions for water surface profiles along a rectangular side weir are available only for triangular, rectangular and trapezoidal primary channels on the basis of constant specific energy. Given that circular channels are an important application in sewer systems, this research presents an elegant semianalytical solution (which involves incomplete elliptic integrals) for establishing the water surface profile along a rectangular side weir located in a circular. The solution is a useful computational tool for the evaluation and design of rectangular side weirs in open circular channels.