Inlet Pressure for Horizontal Tapered Laterals
Publication: Journal of Irrigation and Drainage Engineering
Volume 126, Issue 1
Abstract
Analytical equations are presented for two average pressure correction factors developed for linear displacement laterals with or without outflow at the downstream end. The average correction factor for laterals without downstream outflow, when applied to a relatively large number of outlets is in good agreement with earlier work. For a relatively small number of outlets, the average correction factor presented is more accurate. The average correction factor for laterals with outflow reduces to that for laterals without outflow when the outflow ratio is reduced to zero. For a relatively large number of outlets, this average correction factor is primarily a function of the outflow ratio. For both large outflow ratios and large outlet numbers, the average correction factor is almost a constant. To apply the average correction factor to design a tapered lateral, an expression relating lateral inlet head to required average head and friction head loss has been developed. The expression can be applied to a lateral with any number of reaches with different diameters. A practical application has been demonstrated through an example.
Get full access to this article
View all available purchase options and get full access to this article.
References
1.
Anwar, A. A. (1999). “Factor G for pipelines with equally spaced multiple outlets and outflow.”J. Irrig. and Drain Engrg., ASCE, 125(1), 34–39.
2.
Christiansen, J. E. ( 1942). “Irrigation by sprinkling.” Calif. Agric. Expt. Sta. Bull. No. 670, University of California, Davis, Calif.
3.
Chu, S. T. (1978). “Modified F factor for irrigation laterals.” Trans. ASAE, 21(1), 116–118.
4.
Chu, S. T. (1972). “Hydraulics of a center pivot system.” Trans. ASAE, 15(5), 894–896.
5.
Churchill, S. W. (1977). “Friction-factor equation spans all fluid-flow regimes.” Chemical Engrg., London, 84(24), 91–92.
6.
Detar, W. R. (1982). “Modified graphical determination of submain size.” Trans. ASAE, 25(3), 695–696.
7.
Gilley, J. R. (1989). “Discussion of `Friction correction factor for center-pivot irrigation systems,' by J. Mohan Reddy and Horacio Apolayo.”J. Irrig. and Drain. Engrg., ASCE, 115(4), 769–770.
8.
Heerman, D. F., and Hein, P. R. (1968). “Performance characteristics or self-propelled center-pivot sprinkler irrigation systems.” Trans. ASAE, 11(1), 111–115.
9.
James, L. G. (1988). Principles of farm irrigation system design. Wiley, New York.
10.
Jensen, M. C., and Fratini, A. M. (1957). “Adjusted `F' factors for sprinkler lateral design.” Agric. Engrg., 38(4), 247.
11.
Keller, J., and Bliesner, R. D. (1990). Sprinkle and trickle irrigation. Chapman & Hall, New York.
12.
Kincaid, D. C., and Heerman, D. F. (1970). “Pressure distribution on a center-pivot sprinkler irrigation system.” Trans. ASAE, 13(5), 556–558.
13.
Reddy, J. M., and Apolayo, H. (1988). “Friction correction factor for center-pivot irrigation systems.”J. Irrig. and Drain. Engrg., ASCE, 114(1), 183–185.
14.
Scaloppi, E. J. (1988). “Adjusted F factor for multiple-outlet pipes.”J. Irrig. and Drain. Engrg., ASCE, 114(1), 169–174.
15.
Scaloppi, E. J., and Allen, R. G. (1993a). “Hydraulics of irrigation laterals: Comparative analysis.”J. Irrig. and Drain. Engrg., ASCE, 119(1), 91–115.
16.
Scaloppi, E. J., and Allen, R. G. (1993b). “Hydraulics of center-pivot laterals.”J. Irrig. and Drain. Engrg., ASCE, 199(3), 554–567.
17.
Smith, R. J. (1990). “Discussion of `Adjusted F factor for multiple-outlet pipes,' by Edmar José Scaloppi.”J. Irrig. and Drain. Engrg., ASCE, 116(1), 134–136.
18.
Spiegel, M. R. (1968). Mathematical handbook of formulas and tables. McGraw-Hill, New York.
Information & Authors
Information
Published In
History
Received: Feb 4, 1999
Published online: Jan 1, 2000
Published in print: Jan 2000
Authors
Metrics & Citations
Metrics
Citations
Download citation
If you have the appropriate software installed, you can download article citation data to the citation manager of your choice. Simply select your manager software from the list below and click Download.