Experimental Study of Hydraulic Flow of Circular Piano-Key Inlet in Shaft Spillways

Document Type: Regular Paper

Authors

1 Water Engineering Department, Faculty of Agriculture, Bu-Ali Sina University, Hamadan, Iran

2 Water Engineering Department, Faculty of Agriculture, Ferdowsi University, Mashhad, Iran

3 Young Researchers and Elite Club, Hamedan Branch, Islamic Azad University, Hamedan, Iran

Abstract

One of the most important conflicts that shaft spillways have to deal with is vortex formation. This phenomenon leads to some unfavorable effects such as vibration in the body of structures, air entrainment and reduced overflow capacity of the spillway. Among all solutions for disrupted vortex formation, an innovative one called circular piano-key spillway, based upon piano key weir principles has not been noticed as well as other solutions. Hence, in this study, experiments were conducted on circular piano-key spillway models. Results showed that in a constant head, the greater amounts of discharge have been measured for circular piano key inlet with an angle of 90 degrees. Comparison between discharge coefficients of three circular piano key inlet models showed that for a constant amount of H/D (Head/Diameter), circular piano key inlet with an angle of 90, 60 and 45 degrees have the greater amount of discharge coefficients, respectively. Experiment results indicated that circular piano-key spillway (with an angle of 90 degrees) increases overflow discharge capacity about 15.16% compared with shaft spillway. Among circular piano key inlets, the model with an angle of 90 degrees has the best hydraulic performance.

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References

[1] Khatsuria, R. M. (2005). Hydraulics of Spillways and Energy Dissipators. (M. D. Meyer, Ed.). New York: Marcel Dekker.

[2] Ricketts, J. T., Loftin, M. K., & Merritt, F. S. (2004). Standard Handbook for Civil Engineers. McGraw-Hill.

[3] Novak, P., & Cabelka, J. (1981). Models in hydraulic engineering: physical principles & design applications. (pp. 205-222). Pitman Press.

[4] Kabiri-samani, A. R., & Borghei, S. M. (2013). Effects of anti-vortex plates on air entrainment by free vortex. Scientia Iranica, 20(2), 251–258. http://doi.org/10.1016/j.scient.2012.10.041.

[5] Ouamane, A., Lemperiere, F. (2013). “PK Weir – design of a new economic shape of weir.” Symp. Dams in the societies of the 21st century, Barcelona, Spain.

[6] Lempérière, F., & Ouamane, A. (2003). The Piano Keys weir: A new cost-effective solution for spillways. International Journal on Hydropower and Dams.

[7] Barcouda, M., Cazaillet, O., Cochet, P., Jones, B. A., Lacroix, S., Laugier, F., Vigny, J. P. (2006). Cost effective increase in storage and safety of most dams using fusegates or PK Weirs. In 22nd ICOLD Congress (Vol. 22, pp. 1289–1326).

[8] Cicero, G. M., Barcouda, M., & Luck, M. (2011). Study of a piano key morning glory to increase the spillway capacity of the Bage dam. In Proceedings of the International Conference on Labyrinth and Piano Key Weirs - PKW2011 (pp. 81–86). London: Taylor & Francis.

[9] Ancell, W. (2013). Black Esk Reservoir Dam Raising. UK Water Projects 2013, Water Treatment and Supply, 295–297.

[10] www.moore-concrete.com

[11] Ackers, J. C., Bennett, F. C. J., Scott, T. A., & Karunaratne, G. (2014). Raising the bellmouth spillway at Black Esk reservoir using Piano Key Weirs. In Proceedings of the 2nd International Workshop on Labyrinth and Piano Key Weirs - PKW2013 (pp. 235–242).

[12] Shemshi, R., & Kabiri-Samani, A. (2016). Swirling flow at vertical shaft spillways with circular piano-key inlets. Journal of Hydraulic Research, 55(2), 248–258. http://doi.org/10.1080/00221686.2016.1238015.

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History

  • Receive Date: 12 November 2017
  • Revise Date: 04 May 2018
  • Accept Date: 14 July 2018

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