Modified Hazen–Williams and Darcy–Weisbach Equations for Friction and Local Head Losses along Irrigation Laterals
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VIEW THE REPLYPublication: Journal of Irrigation and Drainage Engineering
Volume 131, Issue 4
Abstract
In previous analytical approaches, the direct calculation of friction loss along a lateral is usually based on empirical power-form flow resistance equations, such as the Hazen–Williams and Blasius equations. The more generalized Darcy–Weisbach resistance equation is not usually applied since its friction coefficient varies along the lateral. In this paper, initially, the Darcy–Weisbach and Hazen–Williams equations are systematically compared, leading to a correction form for the Hazen–Williams coefficient. In addition, a more accurate procedure assuming a power function form for the Darcy–Weisbach equation along irrigation laterals is also proposed. The systematic analysis of various typical flow pipe irrigation situations (e.g., sprinkler irrigation laterals of linear or radial-center pivot displacement, trickle irrigation laterals, and manifolds) indicates that the friction loss along laterals calculated using the Darcy–Weisbach equation closely follows a discharge-power form function. The two empirical parameters of the power function depend on the specific pipe characteristics as well as the specific range of discharge values along the lateral. The proposed analytical solution is extended to incorporate the local head loss, the velocity head variation, and the outflow nonuniformity along sprinkler and trickle irrigation laterals. The suggested direct computation solution is demonstrated in two application examples of sprinkler and trickle irrigation laterals and compared with accurate numerical solutions.
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Reference
Anwar, A. A. (1999). “Adjusted factor for pipelines with multiple outlets and outflow.” J. Irrig. Drain. Eng., 125(6), 355–359.
Bagarello, V., Ferro, V., Provenzano, G., and Pumo, D. (1995). “Experimental study of flow resistance law for small diameter plastic pipes.” J. Irrig. Drain. Eng., 121(5), 313–316.
Bagarello, V., Ferro, V., Provenzano, G., and Pumo, D. (1997). “Evaluating pressure losses in drip-irrigation lines.” J. Irrig. Drain. Eng., 123(1), 1–7.
Christiansen, B. A., Locher, F. A., and Swamee, P. K. (2000). “Discussion of Limitations and proper use of the Hazen–Williams equation by Liou C. P.” J. Hydraul. Eng., 126(2), 167–168.
Hathoot, H. M., Abo-Ghobar, H. M., and Al-Amoud, A. I. (1994). “Analysis and design of sprinkler irrigation laterals.” J. Irrig. Drain. Eng., 120(3), 534–549.
Jensen, M. E., Ed. (1981). “Design and operation of farm irrigation systems,” ASAE Monograph, St. Joseph, Mich.
Juana, L., Rodriguez-Sinobas, L., and Losada, A. (2002). “Determining minor head losses in drip irrigation laterals. 1: Methodology.” J. Irrig. Drain. Eng., 128(6), 376–384.
Kang, V., and Nishiyama, S. (1996). “Analysis and design of microirrigation laterals.” J. Irrig. Drain. Eng., 122(2), 75–82.
Keller, J., and Bliesner, R. D., (1990). Sprinkle and trickle irrigation, Chapman & Hall, New York.
Liou, C. P. (1998). “Limitations and proper use of the Hazen-Williams equation.” J. Hydraul. Eng., 124(9), 951–954.
Scaloppi, E. J., and Allen, R. G. (1993a). “Hydraulics of center pivot laterals.” J. Irrig. Drain. Eng., 119(3), 554–567.
Scaloppi, E. J., and Allen, R. G. (1993b). “Hydraulics of irrigation laterals: Comparative analysis,” J. Irrig. Drain. Eng., 119(1), 91–115.
Swamee, P., and Jain, A. (1976). “Explicit equations for pipe flow problems.” J. Hydraul. Div., Am. Soc. Civ. Eng., 102(5), 657–664.
Valiantzas, J. D. (1998). “Analytical approach for direct drip lateral hydraulic calculation.” J. Irrig. Drain. Eng., 124(6), 300–305.
Valiantzas, J. D. (2002). “Continuous outflow variation along irrigation laterals: Effect of the number of outlets.” J. Irrig. Drain. Eng., 128(1), 34–42.
Valiantzas, J. D., and Dercas, N. (2005). “Hydraulic analysis of multidiameter center-pivot sprinkler laterals.” J. Irrig. Drain. Eng., 131(2) xx–xx.
Vallesquino, P., and Luque-Escamilla, P. L. (2002). “Equivalent friction factor method for hydraulic calculation of irrigation laterals.” J. Irrig. Drain. Eng., 128(5), 278–286.
von Bernuth, R. D. (1990). “Simple and accurate friction loss equation for plastic pipe.” J. Irrig. Drain. Eng., 116(2), 294–298.
Watters, G. Z., and Keller, J. (1978). “Trickle irrigation tubing hydraulics.” ASAE Paper No. 78-2015, ASAE, St. Joseph, Mo.
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© 2005 ASCE.
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Received: Jun 18, 2003
Accepted: Sep 28, 2004
Published online: Aug 1, 2005
Published in print: Aug 2005
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