Equations Describing Sprinkler Droplet Velocity
Publication: Journal of Irrigation and Drainage Engineering
Volume 115, Issue 2
Abstract
Previous investigators have used a graphical method to analyze rate of fall of water droplets through still air to show that the drag force of a water droplet is proportional to the second power of the speed. In this paper, the equations describing the movement of a droplet in still air are put in dimensionless form (with the terminal speed as the characteristic term) and analytical solutions are obtained for the horizontal and vertical velocities and displacements of a droplet, given its initial velocity components and the nozzle elevation. The resulting equations may provide a basis for modeling sprinkler distributions. The angle of projection of the droplet as it leaves the nozzle, that results in the maximum horizontal displacement of the droplet when landing on a horizontal surface, is obtained as a function of the speed with which the droplet leaves the nozzle and the elevation of the nozzle. This nozzle angle is designated as the optimum angle.
Get full access to this article
View all available purchase options and get full access to this article.
References
1.
Bilanski, W. K., and Kidder, E. H. (1958). “Factors that affect the distribution of water from a medium‐pressure rotary irrigation sprinkler.” Trans. Amer. Soc. Agric. Eng. 1(1): 19–23, 28.
2.
Green, R. L. (1952). “Evaluation of air resistance to freely falling drops of water.” Agric. Eng. 33(1) 28, (5) 286.
3.
Gunn, R., and Kinzer, G. D. (1949). “The terminal velocity of fall for water droplets in stagnant air.” J. Meteorology 6, 243–248.
4.
Laws, J. O. (1941). “Measurement of the fall‐velocity of water‐drops and raindrops.” Trans. Am. Geophysical Union, 22, 709–721.
5.
Seginer, I. (1965). “Tangential velocity of sprinkler drops.” Trans. Amer. Soc. Agric. Eng. 8(1), 90–93.
6.
Solomon, K. H., Kincaid, D. C., and Bezdek, J. C. (1985). “Drop size distributions for irrigation spray nozzles.” Trans. Amer. Soc. Agric. Eng. 28(6), 1966–1974.
Information & Authors
Information
Published In
Journal of Irrigation and Drainage Engineering
Volume 115 • Issue 2 • April 1989
Pages: 156 - 165
Copyright
Copyright © 1989 ASCE.
History
Published online: Apr 1, 1989
Published in print: Apr 1989
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.