Free overfall in channels with different cross sections and sub-critical flow



In this paper, based on the free vortex theorem and the momentum equation, a theoretical model to predict the pressure head distribution, the pressure coefficient, the end depth ratio (EDR), and flow discharge at the brink of free overfalls in channels of different cross sections with sub-critical flow is presented. Using available experimental and theoretical results of other investigators for rectangular, triangular, exponential, trapezoidal, inverted triangular (Δ-shaped), inverted semicircular and also circular channels, the proposed method has been examined. The presented theory agrees well with the experiments.