Nappe Oscillations on Free-Overfall Structures: Size Scale Effects
Publication: Journal of Hydraulic Engineering
Volume 145, Issue 6
Abstract
Nappe oscillation and its potentially undesirable impact associated with significant noise production can be an issue for free-overfall hydraulic structures. Although nappe oscillation has been observed on various prototype free-overfall structures, this instability behavior may not be evident during the design process in which experimental and/or numerical modeling may be utilized. In addition, previous studies regarding nappe oscillation scalability using similitude or other relationships has received very limited attention in the literature. An experimental study aimed at investigating the possible size scale effects on nappe oscillations was undertaken utilizing two experimental facilities: a prototype-scale linear weir (3-m fall height) and a geometrically similar 1:3-scale model (1-m fall height). The nappe oscillation occurrence assessment and oscillation frequency evaluation were performed using sound and image analyses. Experiments on both models showed that the nappe oscillation phenomenon generally occurs over a fixed range of unit discharge and is independent of size scale. Nappe oscillation can therefore not be reproduced at different model scales according to standard similarity laws. This study also highlights the secondary influences of the crest profile and the fall height on the oscillation characteristics.
Get full access to this article
View all available purchase options and get full access to this article.
Acknowledgments
The first author acknowledges the Fédération Wallonie-Bruxelles for the funding of hers research stay in Utah.
References
Anderson, A., and B. P. Tullis. 2018. “Finite crest length weir nappe oscillation.” J. Hydraul. Eng. 144 (6): 04018020. https://doi.org/10.1061/(ASCE)HY.1943-7900.0001461.
Binnie, A. 1972. “The stability of a falling sheet of water.” Proc. R. Soc. London, Ser. A: Math. Phys. Eng. Sci. 326 (1565): 149–163. https://doi.org/10.1098/rspa.1972.0002.
Casperson, L. W. 1993. “Fluttering fountains.” J. Sound Vibr. 162 (2): 251–262. https://doi.org/10.1006/jsvi.1993.1117.
Castillo, L. G., J. M. Carrillo, and Á. Sordo-Ward. 2014. “Simulation of overflow nappe impingement jets.” J. Hydroinf. 16 (4): 922–940. https://doi.org/10.2166/hydro.2014.109.
Chanson, H. 1996. Some hydraulic aspects during overflow above inflatable flexible membrane dam. Brisbane, Australia: Univ. of Queensland.
Crookston, B. M., A. Anderson, L. Shearin-Feimster, and B. P. Tullis. 2014. “Mitigation investigation of flow-induced vibrations at a rehabilitated spillway.” In Proc., 11th National Conf. on Hydraulics in Civil Engineering and 5th Int. Symp. on Hydraulic Structures: Hydraulic Structures and Society-Engineering Challenges and Extremes, 149–156. Barton, Australia: Engineers Australia.
Ervine, D. A., H. T. Falvey, and W. Withers. 1997. “Pressure fluctuations on plunge pool floors.” J. Hydraul. Res. 35 (2): 257–279. https://doi.org/10.1080/00221689709498430.
Ettema, R., R. Arndt, P. Roberts, and T. Wahl. 2000. Hydraulic modeling: Concepts and practice. Reston, VA: ASCE.
Heller, V. 2011. “Scale effects in physical hydraulic engineering models.” J. Hydraul. Res. 49 (3): 293–306. https://doi.org/10.1080/00221686.2011.578914.
Lodomez, M., B. Bousmar, B. Dewals, P. Archambeau, M. Pirotton, and S. Erpicum. 2018a. “In-situ measurement and mitigation of nappe oscillations—The Papignies and Nisramont dams in Belgium.” In Proc., 7th IAHR Int. Symp. on Hydraulic Structures. Logan, UT: Utah State Univ.
Lodomez, M., M. Pirotton, B. Dewals, P. Archambeau, and S. Erpicum. 2016b. “Frequencies of nappe vibration for free-overfall structures.” In Proc., 6th International Junior Researcher and Engineer Workshop on Hydraulic Structures (IJREWHS). Logan, UT: Utah State Univ.
Lodomez, M., M. Pirotton, B. Dewals, P. Archambeau, and S. Erpicum. 2016a. “Sustainable hydraulics in the era of global change.” In Proc., 4th IAHR Europe Congress. Boca Raton, FL: CRC Press.
Lodomez, M., M. Pirotton, B. Dewals, P. Archambeau, and S. Erpicum. 2017. “Could piano key weirs be subject to nappe oscillations?” In Proc., 3rd Int. Workshop on Labyrinth and Piano Key Weirs (PKW 2017), 135–144. Boca Raton, FL: CRC Press.
Lodomez, M., M. Pirotton, B. Dewals, P. Archambeau, and S. Erpicum. 2018c. “Nappe oscillations on free-overfall structures: Experimental analysis.” J. Hydraul. Eng. 144 (3): 04018001. https://doi.org/10.1061/(ASCE)HY.1943-7900.0001420.
MWSDB (Metropolitan Water, Sewerage, and Drainage Board). 1980. Investigation into spillway discharge noise at Avon Dam: ANCOLD bulletin no. 57, 31–36. Sydney: MWSDB.
Sato, Y., S. Miura, T. Nagamine, S. Morii, and S. Ohkubo. 2007. “Behavior of a falling water sheet.” J. Environ. Eng. 2 (2): 394–406. https://doi.org/10.1299/jee.2.394.
Schmid, P. J., and D. S. Henningson. 2002. “On the stability of a falling liquid curtain.” J. Fluid Mech. 463: 163–171. https://doi.org/10.1017/S002211200200873X.
USBR (US Bureau of Reclamation). 1964. Experience of the Bureau of Reclamation with flow-induced vibrations. Washington, DC: USBR.
Information & Authors
Information
Published In
Journal of Hydraulic Engineering
Volume 145 • Issue 6 • June 2019
Copyright
©2019 American Society of Civil Engineers.
History
Received: Jun 26, 2018
Accepted: Jan 4, 2019
Published online: Apr 9, 2019
Published in print: Jun 1, 2019
Discussion open until: Sep 9, 2019
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.