EDR in circular channels

This paper presents a simplified approach to determine the end depth of a free overfall in horizontal or mildly sloping circular channels. The flow over a free overfall in a circular channel is simulated by that over a sharp-crested weir to calculate the end-depth ratio (EDR). The theoretical model is calibrated by the experimental data, making the coefficient of velocity as a free parameter. The EDR, related to the critical depth, varies almost linearly from 0.72 to 0.74 for a critical depth-diameter ratio up to 0.86. The method of estimation of discharge from the known end depth is also presented.