Transitional and Weir Flow in a Vented Drop Shaft with a Sharp-Edged Intake
Publication: Journal of Irrigation and Drainage Engineering
Volume 142, Issue 5
Abstract
An experimental analysis of a vertical drop shaft with a sharp-edged horizontal intake section and a coaxial venting pipe is undertaken to obtain design criteria given the limited attention provided by literature. Three different flow regimes are observed, namely weir flow and pressurized flow for extreme discharges and transitional flow for intermediate discharges. Particular attention is paid to transitional flow, which is a periodical regime consisting of an alternate switch from weir to pressurized flow, with water heads ranging between a maximum and a minimum. For transitional flow a detailed characterization of water surface oscillations is provided, and nondimensional equations are given describing mean water head, oscillation amplitude and frequency as functions of pipe Froude number and dimensionless plunged length of the coaxial pipe. Also, a region of existence is provided in terms of pipe Froude number and different wave types are identified. For weir flow, a nondimensional head-discharge relation is provided by analogy with overfalls.
Get full access to this article
View all available purchase options and get full access to this article.
References
Anderson, A. G., Vaidyaraman, P., and Chu, C. (1971). “Hydraulics of long vertical conduits and associated cavitation.”, St. Anthony Falls Hydraulics Laboratory, Univ. of Minnesota, Minneapolis.
Anwar, H. O. (1965). “Coefficients of discharge for gravity flow into vertical pipes.” J. Hydraul. Res., 3(1), 1–19.
Banisoltan, S., Rajaratnam, N., and Zhu, D. Z. (2015). “Experimental study of hydraulics of drill-drop manholes.” J. Hydraul. Eng., 04015021.
Del Giudice, G., and Gisonni, C. (2011). “Vortex dropshaft retrofitting: Case of Naples city (Italy).” J. Hydraul. Res., 49(6), 804–808.
Del Giudice, G., Gisonni, C., and Rasulo, G. (2010). “Design of a scroll vortex inlet for supercritical approach flow.” J. Hydraul. Eng., 837–841.
Hager, W. H. (2010). Wastewater hydraulics: Theory and practice, 2nd Ed., Springer, Berlin.
Hager, W. H., and Del Giudice, G. (1998). “Generalized culvert design diagram.” J. Irrig. Drain. Eng., 271–274.
Khatsuria, R. M. (2005). Hydraulics of spillways and energy dissipaters, Civil and Environmental Engineering, New York.
Padulano, R., Del Giudice, G., and Carravetta, A. (2013). “Experimental analysis of a vertical drop shaft.” Water, 5(3), 1380–1392.
Padulano, R., Del Giudice, G., and Carravetta, A. (2015). “Flow regimes in a vertical drop shaft with a sharp-edged intake.” J. Appl. Water Eng. Res., 3(1), 29–34.
Potter, M. C., Wiggert, D. C., and Ramadan, B. H. (2011). Mechanics of fluids, 4th Ed., Cengage Learning, Mason, OH.
USBR. (1987). Design of small dams, U.S. Dept. of the Interior, Bureau of Reclamation, Washington, DC.
Williams, O. (1997). Tunnels and shafts in rock, CECW-ED, Washington, DC.
Information & Authors
Information
Published In
Journal of Irrigation and Drainage Engineering
Volume 142 • Issue 5 • May 2016
Copyright
© 2016 American Society of Civil Engineers.
History
Received: Jun 16, 2015
Accepted: Dec 7, 2015
Published online: Feb 16, 2016
Published in print: May 1, 2016
Discussion open until: Jul 16, 2016
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.