Related Links
Experimental evaluation of free and submerged flow over piano key weirs | ||
| تحقیقات مهندسی سازه های آبیاری و زهکشی | ||
| Article 9, Volume 19, Issue 70, June 2018, Pages 113-126 PDF (651.54 K) | ||
| Document Type: Original Article | ||
| DOI: 10.22092/aridse.2017.108915.1177 | ||
| Authors | ||
| qiumars roushangar* ; mahdi Majedi Asl1; Mohamad taghi alami; jalal shiri2 | ||
| 1Assistant Professor, Maragheh university | ||
| 2Assis.Proff | ||
| Abstract | ||
| The piano key weirs (PKWѕ) are type of nonlinear weirs which can increase the discharge for a given width without the increase in head water .In piano key the length of weir crest in both upstream and downstream can be incresead and therefore can be considered to be a suitable substitution for the labyrinth weirs, with a relatively small footprint In this study, in order to evaluate the Hydraulic performance of PKWs of free & submerged flow, totally 554 experiments are conducted on 11 physical models. Results showed that in the free flow the PK₁.₄ (inlet over outlet key width; wi /w₀=1.4) in the head water ratio of 0.5≤H₀/P≤1 and the PK1.25 in H₀/P≥0.1 as compared with other weirs, has higher Hydraulic performance. In the case of constant values for the wi/w₀ ratio and changing of the floor slope from 1:1.5 to the curve (a quarter of the circle; PKC) the discharge coefficient of these weirs increased about 3 percent. In the condition of submerged flow the value of the submerged upstream head over the free flow of upstream head (H*/H₀) increased by decreasing the submerged upstream head ratio (H₀/P). For the PK1 weir and in the submergence values lower than 0.48, the downstream depth had no effect on upstream depth of weir, and H*=H₀. The modifying of PK₁ causes a decrease the modular submergence range in this weir and occurrence of the full submergence with a little delay. Modifying of PKC₁, lead to an increase in the modular submergence range and no change in the full submergence. | ||
| Keywords | ||
| free and submergence flow; labyrinth weir; Piano Key Weir; submergence ratio | ||
| References | ||
|
Ahadiyan, J. and Afzalian, A. R. 2016. Effect of piers geometric on the hydraulic properties of Piano Key weirs. J. Water Soil Conserv. 23(2): 267-277.
Anderson, R. M. 2011. Piano Key weir head discharge relationships. M.Sc. Thesis. Utah State University, Logan, UT.
Barcouda, M., Cazaillet, O., Cochet, P., Jones, B. A., Lacroix, S., Laugier, F., Odeyer, C. and Vingny, J. P. 2006. Cost-effective increase in storage and safety of most dams using fuse gates or P.K. weirs. Proceeding of the 22nd Congress of ICOLD. Barcelona, Spain.
Dabling, M. R. 2014. Nonlinear weir hydraulics. M. Sc. Thesis. Utah State University, Logan, UT.
Erpicum, S., Nagel, V. and Laugier, F. 2011. Piano Key weir design of raviege dam. Proceeding of International Workshop on Labyrinths and Piano Key Weirs (PKW). CRC Press.
Henderson, F. M. 1966. Open Channel Flow. Macmillan, New York, USA.
Ho Ta Khanh, M., Sy Quat, D. and Xuan Thuy, D. 2011. P. K. weirs under design and construction in
Hien, T. C., Son, H. T. and Khanh, M. H. T. 2006. Results of some Piano Keys weir hydraulic model tests in Vietnam. Proceeding of the 22nd Congress of ICOLD. Barcelona, Spain.
Kabiri-Samani, A. R., Ansari, A. and Borghei, S. M. 2010. Hydraulic behaviour of flow over an oblique weir. J. Hydraul. Res. 48(5): 669-673.
Laugier, F., Lochu, A., Gille, C., Leite Ribeiro, M. and Boillat, J. L. 2009. Design and construction a labyrinth PKW spillway at St-Marc dam, France. Int. J. Hydropower Dam. 15(5): 100-107.
Laugier, F. 2007. Design and construction of the first Piano Key Weir (PKW) spillway at the Goulours dam. Int. J. Hydropower Dam. 13(5): 94-100.
Lempérière, F. 2009. New Labyrinth weirs triple the spillways discharge. Available at: http://www.hydrocoop.org.
Lempérière, F. and Ouamane, A. 2003. The Piano Keys weir: a new cost-effective solution for spillways. Int. J. Hydropower Dam. 9(5): 144-149.
Lempérière, F. and Jun, G. 2005. Low cost increase of dams storage and flood mitigation: the Piano Keys weir. Proceeding of 19th Congress of ICID. Beijing, China.
Ouamane, A. and Lempérière, F. 2006. Design of a new economic shape of weir. Proceeding of the International Symposium of Dams in the Societies of the 21st Century, Barcelona, Spain.
Pinchard, T. Boutet, J. M. and Cicero, G. M. 2011. Spillway capacity upgrade at Malarce dam: design of an additional Piano Key Weir spillway. Proceeding of the International Workshop on Labyrinths and Piano Key Weirs (PKW). CRC Press.
Ribeiro, M. L., Boillat, J. L., Schleiss, A., Laugier, F. and Albalat, C. 2007. Rehabilitation of St-Marc dam- experimental optimization of a Piano Key Weir. Proceeding of 32nd Congress of IAHR. Vince, Italy.
Takhti, F. 2016. The study of geometrical and hydraulic parameters on long-crested weir discharge coefficient (Piano Keys) in free flow mode. M. Sc. Thesis- Bu-Ali-Sina University. Hamedan, Iran.
Tullis, P., Amanian, N. and Waldron, D. 1995. Design of labyrinth weir spillways. J. Hydraul. Eng. ASCE. 121(3): 247-255.
Willmore, C. M. 2004. Hydraulic Characteristics of Labyrinth Weirs. All Graduate Plan B and other Reports. 851.
Yarmohammadi, B. and Ahadiyan, J. 2016. Experimental study of flow hydraulic in Piano Key Weirs at different parapet wall. J. Irrig. Sci. Eng. 39 (4): 47-58. doi:10.22055/jise.2016.12495.
Zerihun, Y. T. and Fenton, J. D. 2007. A Boussinesq-type model for flow over trapezoidal profile weirs. J. Hydraul. Res. 45(4): 519-528. | ||
|
Statistics Article View: 1,860 PDF Download: 764 |
||
Journal management system. designed by sinaweb