Discharge Coefficient of Sharp-Crested Trapezoidal Labyrinth Weirs

Öz

Labyrinth weirs provide an effective means to increase the spillway discharge capacity of dams and are often considered for renovation projects required due to an increase in expected flood inflow to the reservoir of an existing dam. Free crest spillways are hydraulically efficient and safe in operation. Since their discharge capacity is directly proportional to the crest length several types have been developed with the purpose to increase the length of the latter. In recent years many research investigations have considered the hydraulic performance of labyrinth weirs, particularly as dependent on the geometric features. The previous work has improved the design basis for such weirs. In the present study, discharge coefficients were experimentally determined for sharp crested trapezoidal labyrinth weirs of varying side wall angle (α). The experimental results of 21 physical models were used to develop a hydraulic design and analysis method for labyrinth weirs. The present research primarily aims at evaluating various characteristics of a flow-over labyrinth weir by conducting experimentations at wider range of values for important parameters.

Anahtar Kelimeler

• Fluid mechanics,weir,discharge coefficient,trapezoidal,labyrinth weir

Kaynakça

1. Yildiz, D., Uzucek E. (1993) Labirent dolusavaklarn projelendirilme kriterleri. Devlet Su İşleri Teknik Araştrma Kalite ve Kontrol Dairesi Başkanlğ. Yayn No: HI- 862 Ankara.
2. Crookston, B. M., and Tullis, B. P. (2012b) Labyrinth weirs: Nappe interference and local submergence. J. Irrig. Drain. Eng., 138(8), 757–765.
3. Yildiz, D., Uzucek, E. (1996) Modeling the performance of labyrinth spillways. Int. J. Hydropower Dams, 3, 71–76.
4. Tsang, C. (1987) Hydraulic and aeration performance of labyrinth weirs. Ph.D. dissertation, University of London, London.
5. Taylor, G. (1968). The performance oflabyrinth weirs. PhD thesis, University of Nottingham, U.K.
6. Hay, N., and Taylor, G. (1970) Performance and design of labyrinth weir. J. Hydraul. Eng., 96(11), 2337–2357.
7. Darvas, L. (1971) Discussion of performance and design of labyrinth weirs, by Hay and Taylor. J. Hydraul. Eng., ASCE, 97(80), 1246–1251.
8. Houston, K. (1982) Hydraulic model study of Ute dam labyrinth spillway. Rep. No. GR-82- 7, U.S. Bureau of Reclamation, Denver.

9. Houston, K. (1983) Hydraulic model study of Hyrum dam auxiliary labyrinth spillway. Rep. No. GR-82-13, U.S. Bureau of Reclamation, Denver.
10. Lux, F., (1989) Design and Application of Labyrinth Weirs, Design of Hydraulic Structures 89, Balkema, Rotterdam, ISBN, 90, 6191 – 8987.
11. Magalhaes, A., and Lorena, M. (1989) Hydraulic design of labyrinth weirs. Rep. No. 736, National Laboratory of Civil Engineering, Lisbon, Portugal.
12. Tullis, B. P., Amanian, N., and Waldron, D. (1995) Design of labyrinth weir spillways. J. Hydraul. Eng., ASCE, 121(3), 247–255.
13. Tullis, B. P., Young, J., and Chandler, M. (2007) Head-discharge relationships for submerged labyrinth weirs. J. of Hydraul. Eng., ASCE, 133(3), 248–254.
14. Savage, B., Frizell, K., and Crowder, J. (2004) Brains versus brawn: The changing world of hydraulic model studies. ASDSO 2004 Annual Conf. Proc., Association of State Dam Safety Officials (ASDSO), Lexington, KY. (May 4, 2009).
15. Emiroglu, M. E., Kaya, N., and Agaccioglu, H. (2010).“Discharge capacity of labyrinth side weir located on a straight channel.”J. Irrig. Drain. Eng., ASCE, 136(1), 37–46.
16. Bilhan, O, Emiroglu, M. E., Kisi, O, (2010) Use of artificial neural networks for prediction of discharge coefficient of triangular labyrinth side weir in curved channels. J. Advances in Eng. Soft. 42(4), 208-214.
17. Khode, B.V., Tembhurkar, A.R. Porey, P.D. and Ingle R.N. (2011) Determination of Crest Coefficient for Flow over Trapezoidal Labyrinth Weir. World Applied Sciences Journal 12 (3): 324-329.
18. Khode, B. V., Tembhurkar, A. R. P. D. Porey and R. N. Ingle, (2012) Experimental Studies on Flow over Labyrinth Weir. Journal of Irrig. Drain Eng. ASCE, 138:548-552.
19. Anderson, R. M. and Tullis, B. P., (2012) Comparison of Piano Key and Rectangular Labyrinth Weir Hydraulics. J. Hydraul. Eng. 138:358-361.
20. Crookston, B. M., and Tullis, B. P. (2012a) Arced labyrinth weirs. J. Hydraul. Eng., 138(6), 555–562.
21. Crookston, B. M. and Tullis, B. P. (2013) Hydraulic Design and Analysis of Labyrinth Weirs. II: Nappe Aeration, Instability, and Vibration. J. Irrig. Drain Eng., ASCE, 139(5), 371–377.
22. Emiroglu M. E., Omer Bilhan, “Investigation of discharge coefficient of labyrinth weirs and using nape breakers on this weirs.” Project No: 1610, Firat University, FUBAP, 2009, Turkey.
23. Hinchliff, D., and Houston, K. (1984). Hydraulic design and application of labyrinth spillways. Proc., 4th Annual USCOLD Lecture, Dam Safety and Rehabilitation, Bureau of Reclamation, U.S. Dept. of the Interior, Washington, DC.
24. Lux and Hinchliff, (1985). “Discharge construction of labyrinth spillway.” Transactions of 15th congress of international Committee on large Dam. Lausanne Switzerland, pp: 249-274.
25. Melo, J., Ramos, C., and Magalhães, A. (2002) “Descarregadores com soleira em labirinto de um ciclo em canais convergentes. Determinação da capacidad de vazão”. Proc. 6o Congresso da Água (CD-ROM), Associação Portuguesa dos Recursos Hídricos, Lisboa, Portugal.
26. Lopez, R., Matos, J. and Melo, J. (2008) “Characteristic depths and energy dissipation downstream of a labyrinth weir.” 2nd Int. Junior Researcher and Engineer Workshop on Hydraulic Structures, Pisa, Italia.
27. Babb, A. (1976). “Hydraulic model study of the Boardman Reservoir Spillway.” R.L Albrook Hydraulic Laboratory, Washington State University, Pullman, Wash.