Statistical Analysis of Non-Pressure-Compensating and Pressure-Compensating Drip Emitters
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VIEW THE REPLYPublication: Journal of Irrigation and Drainage Engineering
Volume 139, Issue 12
Abstract
Drip irrigation may need to be installed in situations in which there is not enough energy to operate the emitters under optimum performance conditions. This paper characterizes the head-discharge functional form of a pressure-compensated (PC) and non-pressure-compensating (NPC) drip emitter operating under low pressures. It also analyzes the statistical relationship between manufacturing and hydraulic variations of low-pressure operating emitters assuming that both are independent random variables. A hydraulic simulation methodology was implemented to predict the effect of emitter manufacturing and hydraulic variations on irrigation uniformity while working under a range of operating pressures. The manufacturing variation of PC and NPC emitters was evaluated with the Monte Carlo method for a single horizontal drip line with different pressure heads and different numbers of emitters evenly spaced. The coefficient of manufacturing variation () observed in the laboratory was 9.2% for PC (Toro) emitters and 3.8% for NPC (-tape) emitters. Laboratory test results showed that manufacturing and hydraulic factors were stochastic independent variables, and this independent relationship allowed the combination of statistics for estimating the coefficient of total variation. The manufacturing emitter variation has a considerable impact on low-quarter distribution uniformity (), as the number of emitters in the drip line is increased. For instance, the of the PC (Toro) emitter decreased considerably from 1.0 to 0.82 compared with the NPC (T-tape) emitter, which varied from 0.943 to 0.939 when the length was increased from 60 to 200 emitters long drip line. The PC emitter started compensating at 6.16 m of hydraulic head. Therefore, this type of emitter is not recommended for low operating pressure systems. It is recommended to design low-pressure irrigation systems with the right emitter type and operating pressure to maximize performance.
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Acknowledgments
This paper is a contribution from the Department of Biological and Agricultural Engineering and Texas A&M AgriLife Research. The writers wish to acknowledge Dr. Bert Clemmens and Dr. Eduardo Bautista from Arid-Land Research Center, ARS-USDA in Maricopa, Arizona, and Dr. Paul Colaizzi from Conservation and Production Research Laboratory, ARS-USDA in Bushland, Texas, for reviewing this paper.
References
American Society of Agricultural, and Biological Engineers (ASABE). (2008). Design and installation of microirrigation systems, 50th Ed., St. Joseph, MI.
American Society of Agricultural Engineers (ASAE). (1999). Field evaluation of microirrigation systems, 46th Ed., St. Joseph, MI.
Barnett, H. A. R. (1955). “The variance of the product of two independent variables and its application to an investigation based on sample data.” J. Inst. of Actuaries, 81, 190.
Barragan, J., Bralts, V., and Wu, I. P. (2006). “Assessment of emission uniformity for micro-irrigation design.” Biosyst. Eng., 93(1), 89–97.
Bralts, V. F., Wu, I.-P., and Gitlin, H. M. (1981a). “Drip irrigation uniformity considering emitter plugging.” Trans. ASAE, 24(5), 1234–1240.
Bralts, V. F., Wu, I. P., and Gitlin, H. M. (1981b). “Manufacturing variation and drip irrigation uniformity.” Trans. ASAE, 24, 113–119.
Burt, C. M., et al. (1997). “Irrigation performance measures: Efficiency and uniformity.” J. Irrig. Drain. Eng., 423–442.
Buslenko, N. P., Golenko, D. I., Shreider, A., Sobol, I. M., and Sragovich, V. G. (1966). Monte Carlo method: The method of statistical trials, Pergamon Press, Oxford, 378.
Camp, C. R. (1998). “Subsurface drip irrigation: A review.” Trans. ASABE, 41(5), 1353–1367.
Clark, G. A., Lamm, F. R., and Rogers, D. H. (2005). “Sensitivity of thin-walled drip tape emitter discharge to water temperature.” Appl. Eng. Agric., 21(5), 855–863.
Clemmens, A. J. (1987). “A statistical analysis of trickle irrigation uniformity.” Trans. ASAE, 30(1), 169–175.
Debba, P. D. (2008) “Characterization of drip emitters and computing distribution uniformity in a drip irrigation system at low pressure under uniform land slopes.” M. Sc. thesis, Dept. of Biological and Agricultural Engineering, Texas A&M Univ., College Station, TX.
Duan, X. (2006). “Characterization of wastewater subsurface drip emitters and design approaches concerning system application uniformity.” M. Sc. thesis, Dept. of Biological and Agricultural Engineering, Texas A&M Univ., College Station, TX.
Goodman, L. A. (1962). “The variance of the product of K random variables.” J. Am. Stat. Assoc., 57(297), 54–60.
Hathoot, H. M., Al-Amoud, A. I., and Mohammad, F. S. (1993). “Analysis and design of trickle irrigation laterals.” J. Irrig. Drain. Eng., 756–767.
Juana, L., Rodriguez-Sinobas, L., and Losada, A. (2002). “Determining minor head losses in drip irrigation laterals. I: Methodology.” J. Irrig. Drain. Eng., 376–384.
Keller, J., and Bliesner, R. D. (1990). Sprinkler and trickle irrigation, Van Nostrand Reinhold, New York.
Keller, J., and Karmeli, D. (1975). “Trickle irrigation design.” Rainbird Sprinkler Manufacturing, Glendora, CA.
Lamm, F. R., and Camp, C. R. (2007). “Subsurface drip irrigation.” Chapter 13, Microirrigation for crop production—Design, operation and management, F. R. Lamm, J. E. Ayars, and F. S. Nakayama, eds., Elsevier Publications, Amsterdam, 473–551.
Polak, P., Nanes, B., and Adhikari, D. (1997). “A low-cost drip irrigation system for small farmers in developing countries.” J. Am. Water Resour. Assoc., 33(1), 119–124.
Postel, S., Polak, P., Gonzales, F., and Keller, J. (2001). “Drip irrigation for small farmers. A new initiative to alleviate hunger and poverty.” Water Int., 26(1), 3–13.
Provenzano, G., and Pumo, D. (2004). “Experimental analysis of local pressure losses for drip irrigation laterals.” J. Irrig. Drain. Eng., 318–324.
Provenzano, G., Pumo, D., and Di Dio, P. (2005). “A simplified procedure to design drip irrigation laterals.” J. Irrig. Drain. Eng., 525–532.
Sinobas, L. R., Juana, L., and Losada, A. (1999). “Effects of temperature changes on emitter discharge.” J. Irrig. Drain. Eng., 64–73.
Solomon, K. (1979). “Manufacturing variation of trickle emitters.” Trans. ASAE, 22(5), 1034–1038.
Solomon, K. H. (1984). “Global uniformity of trickle irrigation systems.”, American Society of Agricultural Enginers, St. Joseph, MI.
Solomon, K. H. (1985). “Yield related interpretations of irrigation uniformity and efficiency measures.” Irrig. Sci., 5(3), 161–172.
von Bernuth, R. D. (1990). “Simple and accurate friction loss equation for plastic pipe.” J. Irrig. Drain. Eng., 294–298.
Yıldırım, G. (2006a). “Discussion of ‘Experimental analysis of local pressure losses for drip irrigation laterals’ by Giuseppe Provenzano and Domenico Pumo.” J. Irrig. Drain. Eng., 189–192.
Yıldırım, G. (2006b). “Hydraulic analysis and direct design of multiple outlets pipelines laid on flat and sloping lands.” J. Irrig. Drain. Eng., 537–552.
Yıldırım, G. (2007). “An assessment of hydraulic design of trickle laterals considering effect of minor losses.” Irrig. Drain., 56(4), 399–421.
Yıldırım, G., and Ağıralioğlu, N. (2008). “Determining operating inlet pressure head incorporating uniformity parameters for multioutlet plastic pipelines.” J. Irrig. Drain. Eng., 341–348.
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Published In
Journal of Irrigation and Drainage Engineering
Volume 139 • Issue 12 • December 2013
Pages: 986 - 994
Copyright
© 2013 American Society of Civil Engineers.
History
Received: Jan 8, 2013
Accepted: Jun 6, 2013
Published online: Jun 8, 2013
Discussion open until: Nov 8, 2013
Published in print: Dec 1, 2013
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