Abstract:The structure, flow measurement principle and design method of long-throated flumes are described. Applying the continuity equation and the energy equation of flow ,the fundamental principle of hydraulic calculation for long-throated flumes is discussed. The head loss of fluid which flows through the long-throated flume is analyzed by using the boundary layer theory. A method for calculating the relationship between water level and discharge of long-throated flume is obtained. Long-throated flumes can be calibrated using computer programs, thus eliminating the need for laboratory calibration. The field testing showed that the calculating method can predict the measured flow rate with less than 5% error.
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