Effects of a Labyrinth Weir with Outlet Ramps on Downstream Steep-Stepped Chute Sidewall Height Requirements
Publication: Journal of Irrigation and Drainage Engineering
Volume 147, Issue 12
Abstract
Labyrinth weirs are commonly used to increase spillway discharge capacity. Stepped chutes represent a common spillway element used to help dissipate kinetic energy, thus reducing the size requirement and often the cost of the downstream energy dissipation basin. When combined, the complex, highly turbulent, aerated flow patterns generated by the labyrinth weir create different aeration inception point behaviors relative to traditional stepped chute applications (e.g., linear weir upstream). To reduce the risk of erosion and other damage near the spillway, stepped chute sidewalls are typically designed with sufficient height to contain the majority, if not all, of the bulked air-water spillway flow and surface waves. This study evaluated some of the hydraulic impacts of coupling a labyrinth weir with a relatively steep-stepped chute (08H:1V) at the laboratory scale in an effort to provide some useful guidance related to the sizing stepped chute wall heights. Test results showed that required chute wall heights for bulked flow containments were higher at the chute entrance than the traditional stepped chute (i.e., no labyrinth weir) design predictions. Placing ramped floors in the labyrinth weir downstream cycles facilitates the transition from the labyrinth outlet cycles to the steep chute and, in some cases, reduced maximum chute water levels. To better understand this phenomenon and provide guidance toward the use of ramped floors to reduce chute wall height requirements, the hydraulic behavior of various ramped floor configurations was systematically evaluated. The results for the geometries tested ranged from no effect to a 15% reduction in maximum chute flow depth.
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Data Availability Statement
Some or all data that support the findings of this study are available from the corresponding author upon reasonable request. Specifically, the Utah State University experimental data in tabular and graphical forms are available from the corresponding author upon reasonable request.
Acknowledgments
This study was funded by the State of Utah and the Utah Water Research Laboratory at Utah State University.
References
Bieri, M., M. Fererspiel, and J.-L. Boillat. 2011. “Energy dissipation downstream of piano key weirs-case study of Gloriettes Dam (France).” In Labyrinth and piano key weirs—PKW 2011, 123–130. London: CRC Press.
Boes, R. M., and W. H. Hager. 2003. “Hydraulic design of stepped spillways.” J. Hydraul. Eng. 129 (9): 671–679. https://doi.org/10.1061/(ASCE)0733-9429(2003)129:9(671).
Chamani, M. R. 1997. “Skimming flow in a large model of a stepped spillway.” Ph.D. dissertations, Dept. of Civil Engineering, Univ. of Alberta.
Chanson, H. 1994. Hydraulic design of stepped cascades, channels, weirs, and spillways. Tarrytown, NY: Elsevier.
Chanson, H. 2002. The hydraulics of stepped chutes and spillways. Exton, PA: A.A. Balkema.
Chanson, H. 2006. “Hydraulics of skimming flows on stepped chutes: The effects of inflow conditions?” J. Hydraul. Res. 44 (1): 51–60. https://doi.org/10.1080/00221686.2006.9521660.
Chanson, H. 2009. “Current knowledge in hydraulic jumps and related phenomena: A survey of experimental results.” Eur. J. Mech. B. Fluids 28 (2): 191–210. https://doi.org/10.1016/j.euromechflu.2008.06.004.
Chanson, H., and L. Toombes. 2002. “Experimental investigations of air entrainment in transition and skimming flows down a stepped chute.” Can. J. Civ. Eng. 29 (1): 145–156. https://doi.org/10.1139/l01-084.
Crookston, B. M., and B. P. Tullis. 2013. “Hydraulic design and analysis of labyrinth weirs. II: Nappe aeration, instability, and vibration.” J. Irrig. Drain. Eng. 139 (5): 371–377. https://doi.org/10.1061/(ASCE)IR.1943-4774.0000553.
Erpicum, S., O. Machiels, P. Archambeau, B. Dewals, and M. Pirotton. 2011. “Energy dissipation on a stepped spillway downstream of a piano key weir-experimental study.” In Labyrinth and piano key weirs—PKW 2011, 105–111. London: CRC Press.
Felder, S. 2013. “Air-water flow properties on stepped spillways for embankment dams: Aeration, energy dissipation and turbulence on uniform, non-uniform, and pooled stepped chutes.” Ph.D. thesis, School of Civil Engineering, Univ. of Queensland.
Felder, S., and H. Chanson. 2009. “Turbulence, dynamic similarity and scale effects in high-velocity free-surface flows above a stepped chute.” Exp. Fluids 47 (1): 1–18. https://doi.org/10.1007/s00348-009-0628-3.
Felder, S., and H. Chanson. 2017. “Scale effects in microscopic air-water flow properties in high-velocity free-surface flows.” Exp. Therm. Fluid Sci. 83 (5): 19–36. https://doi.org/10.1016/j.expthermflusci.2016.12.009.
Gonzalez, C. A. 2005. “An experimental study of free-surface aeration on embankment stepped chutes.” Ph.D. thesis, School of Civil Engineering, Univ. of Queensland.
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.
Ho Ta Kahn, M., D. Sy Quat, and D. Xuan Thuy. 2011. “P.K. weirs under design and construction in Vietnam.” In Labyrinth and piano key weirs—PKW 2011, 225–232. London: CRC Press.
Hunt, S. L., and K. C. Kadavy. 2017. “Estimated splash and training wall height requirements for stepped chutes applied to embankment dams.” J. Hydraul. Eng. 143 (11): 06017018. https://doi.org/10.1061/(ASCE)HY.1943-7900.0001373.
Jorgensen, T. 2020. “Hydraulic analysis of coupling a labyrinth weir with a steep stepped chute.” M.S. thesis. Dept. of Civil and Environmental Engineering, Utah State Univ.
Jorgensen, T., B. P. Tullis, and B. M. Crookston. 2021. “Labyrinth weirs outlet ramps: Managing flow instability and discharge efficiency.” In Proc., Institution of Civil Engineers-Water Management. London: Thomas Telford Ltd. https://doi.org/10.1680/jwama.20.00061.
Kobus, H., ed. 1980. Hydraulic modeling. Hamburg, Germany: German Association for Water Resources and Land Improvement.
Loisle, P. E., P. Valley, and F. Laugier. 2014. “Hydraulic physical model of piano key weirs as additional flood spillways on the Charmine Dam.” In Labyrinth and piano key weirs II: PKW 2013, edited by S. Erpicum, 195–202. London: CRC Press.
Rajaratnam, R. 1990. “Skimming flow in stepped spillways.” J. Hydraul. Eng. 116 (4): 587–591. https://doi.org/10.1061/(ASCE)0733-9429(1990)116:4(587).
Ruff, J. F., and J. P. Ward. 2002. Hydraulic design of stepped spillways. Denver: US Bureau of Reclamation.
Toombes, L. 2002. “Experimental study of air-water flow properties on low-gradient stepped cascades.” Ph.D. thesis, School of Civil Engineering, Univ. of Queensland.
Valero, D. 2018. “On the fluid mechanics of self-aeration in open channel flows.” Ph.D. dissertation, Dept. of Architecture, Geology, Environment and Contraction, Univ. of Liege.
Valero, D., H. Chanson, and D. B. Bung. 2020. “Robust estimators for free surface turbulence characterization: A stepped spillway application.” Flow Meas. Instrum. 76 (Dec): 101809. https://doi.org/10.1016/j.flowmeasinst.2020.101809.
Zhang, G. 2017. “Free-surface aeration, turbulence, and energy dissipation on stepped chutes with triangular steps, chamfered steps, and partially blocked step cavities.” Ph.D. thesis, School of Civil Engineering, Univ. of Queensland.
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Received: Feb 25, 2021
Accepted: Aug 18, 2021
Published online: Sep 23, 2021
Published in print: Dec 1, 2021
Discussion open until: Feb 23, 2022
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