Reports > Flow Rate Equation for Suppressed and Submerged Sluice Gates
Flow Rate Equation for Suppressed and Submerged Sluice Gates
In irrigation projects, the control and measurement of flow rates at key bifurcation points is essential. Sluice gates at the heads of irrigation canals are used by operators to control the flow into these canals. In US irrigation districts, canal operators often estimate flow rate at the heads of canals by “experience” unless they have a flume downstream. For example, they may open a gate a certain number of turns for a change in flow rate, regardless of upstream and downstream conditions. Theoretical estimates of discharge are often inaccurate in field situations. Problems include varying and uncertain discharge coefficients, entrance and exit conditions, floor steps, gate orientation, sensor locations, free and submerged conditions, etc. Automatic control of flow rate with electronic devices (for example, programmable logic controllers) has been challenging at canal headgates because of uncertainties of what formulas and coefficients to use. Other devices are often not practical at these locations (flumes may require too much head loss, ultrasonic meters need long averaging periods, etc.). This paper develops calibration equations for one particular sluice gate configuration so that it can be used for automation of canal headgates. It modifies empirical methods used by others. With this method, the standard deviation of discharge predication is within 4.5 percent.
Burt, C.M., A.J. Clemmens, and K. Feist. 2020. Flow Rate Equation for Suppressed and Submerged Sluice Gates Irrigation Training & Research Center, California Polytechnic State University, San Luis Obispo, California, USA. ITRC Report No. R 20-001. 18 pp.
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