Overfall in U-Shaped Channels

Free overfall in U-shaped channels is theoretically analyzed, applying a momentum equation based on the Boussinesq approximation, to obtain the equation of end depth. The end-depth ratio is 0.75 up to normalized critical depth 0.50; and then it decreases gradually with an increase in normalized critical depth. A method to estimate discharge from the end depth is presented. The upstream flow profile of a free overfall is computed using the streamline curvature at the free surface. Experiments were conducted in two U-shaped channels to verify the model. The results obtained using the model agree satisfactorily with the experimental data.