Discharge and mechanical efficiency of Egyptian water - lifting wheels

Data on 35 spiral-shaped waterwheels from the Mansuriya and Kafr El-Sheikh regions of Egypt were used to develop a field procedure for calibrating the discharge per revolution relative to the percent of submergence of the wheel. Thus, the rate and quantity of water applied to a field could be determined using data on the number of revolutions and the change in submergence of the wheel over time. A typical discharge per revolution of a 3-m diameter wheel, lifting water 75 cm, was 600 liters per revolution. In addition, a procedure was developed to determine a wheel"s mechanical efficiency from field data. Data on 11 waterwheels from the Kafr El-Sheikh area were analyzed; the data indicated that a well-designed and maintained installation might be expected to have a mechanical efficiency of 45%. (Author abstract, modified)