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Numerical Investigation of the Effect of CEDEX Profile on the Hydraulic Parameters in the Stepped Spillway and the Performance of This Profile in Various Chute Slopes

  • Kazem Dalili KhanghahEmail author
  • M. R. Kavianpour
Research Paper
  • 1 Downloads

Abstract

An important part in designing stepped spillways is making the spillway in order to direct the flow appropriately on the first step. In low discharges, the water flow moves over the spillway and arrives at the first step, and if the first step is high enough, the flow may leave the first step horizontally, skip some steps and land as a free jet of water on the lower steps, which might cause some damages to the structure. One of the solutions to this problem is to use CEDEX profile, transition steps between the ogee crest and the stepped chute. The present research carries out a numerical study of the effects of CEDEX profile on various hydraulic parameters and also the effects of the chute slope on the performance of this profile in preventing the flow jump. For this purpose, four models were created with different geometries and were studied in various discharges with FLOW-3D software. The results show that deploying CEDEX profile in the initial parts of the spillway leads to lower velocity and less risk of cavitation. Also, the results illustrate that CEDEX profile can shift the inception point of aeration to downstream. Furthermore, findings show that CEDEX profile, in the slope of less than 50°, can prevent flow jump in the first step. In steeper slopes, however, it fails to achieve the optimal performance.

Keywords

Stepped spillways CEDEX profile FLOW-3D Flow jet Chute slope 

References

  1. Amador A, Sánchez-Tembleque F, Sánchez-Juny M, Puertas J, Dolz J (2004) Velocity and pressure field in skimming flow in stepped spillways. Taylor & Francis, London, pp 279–286Google Scholar
  2. Amador A, Sánchez-Juny M, Dolz J (2009) Developing flow region and pressure fluctuations on steeply sloping stepped spillways. J Hydraul Eng 135(12):1092–1100.  https://doi.org/10.1061/(asce)hy.1943-7900.0000118 CrossRefGoogle Scholar
  3. Baylar A, Emiroglu ME, Bagatur T (2006) An experimental investigation of aeration performance in stepped spillways. Water Environ J 20(1):35–42.  https://doi.org/10.1111/j.1747-6593.2005.00009.x CrossRefGoogle Scholar
  4. Bombardelli FA, Meireles I, Matos J (2010) Laboratory measurements and multi-block numerical simulations of the mean flow and turbulence in the non-aerated skimming flow region of steep stepped spillways. Environ Fluid Mech 11(3):263–288.  https://doi.org/10.1007/s10652-010-9188-6 CrossRefGoogle Scholar
  5. Chamani MR, Rajaratnam N (1999) Onset of Skimming Flow on Stepped Spillways. J Hydraul Eng 125(9):969–971.  https://doi.org/10.1061/(asce)0733-9429(1999)125:9(969) CrossRefGoogle Scholar
  6. Chanson H (1994) Hydraulics of skimming flows over stepped channels and spillways. J Hydraul Res 32(3):445–460.  https://doi.org/10.1080/00221689409498745 CrossRefGoogle Scholar
  7. Chanson H (1996) Prediction of the transition nappe/skimming flow on a stepped channel. J Hydraul Res 34(3):421–429.  https://doi.org/10.1080/00221689609498490 CrossRefGoogle Scholar
  8. Chanson H (2002) Hydraulics of stepped chutes and spillways. CRC Press, Boca RatonGoogle Scholar
  9. Chen Q, Dai G, Liu H (2002) Volume of fluid model for turbulence numerical simulation of stepped spillway overflow. J Hydraul Eng 128(7):683–688.  https://doi.org/10.1061/(asce)0733-9429(2002)128:7(683) CrossRefGoogle Scholar
  10. Cheng X, Chen Y, Luo L (2006) Numerical simulation of air-water two-phase flow over stepped spillways. Sci China Ser E: Technol Sci 49(6):674–684.  https://doi.org/10.1007/s10288-006-2029-2 CrossRefzbMATHGoogle Scholar
  11. Christodoulou GC (1993) Energy dissipation on stepped spillways. J Hydraul Eng 119(5):644–650.  https://doi.org/10.1061/(asce)0733-9429(1993)119:5(644) CrossRefGoogle Scholar
  12. De Carvalho RF, Amador AT (2009) Physical and numerical investigation of the skimming flow over a stepped spillway. Adv Water Resour Hydraul Eng.  https://doi.org/10.1007/978-3-540-89465-0_304 CrossRefGoogle Scholar
  13. Falvey HT (1990) Cavitation in chutes and spillways. US Department of the Interior, Bureau of ReclamationGoogle Scholar
  14. Frizell KW, Renna FM, Matos J (2013) Cavitation potential of flow on stepped spillways. J Hydraul Eng 139(6):630–636.  https://doi.org/10.1061/(asce)hy.1943-7900.0000715 CrossRefGoogle Scholar
  15. Hamedi A, Hajigholizadeh M, Mansoori A (2016) Flow simulation and energy loss estimation in the nappe flow regime of stepped spillways with inclined steps and end sill: a numerical approach. Civ Eng J 2(9):426–437CrossRefGoogle Scholar
  16. Hirt CW, Nichols B (1988) Flow-3D user’s manual. Flow Science Inc, Santa Fe, p 107Google Scholar
  17. Hunt SL, Kadavy KC (2013) Inception point for embankment dam stepped spillways. J Hydraul Eng 139(1):60–64.  https://doi.org/10.1061/(asce)hy.1943-7900.0000644 CrossRefGoogle Scholar
  18. Javeh Dam hydraulic studies, Final Report (2011) Iran Water Research Institute, Tehran, IranGoogle Scholar
  19. Liao HS, Wu CG (1995) Numerical model of stepped spillway overflow. In: Proceedings of 2nd international conference on hydro-science and engineeringGoogle Scholar
  20. Mansoori A, Erfanian S, Moghadam FK (2017) A study of the conditions of energy dissipation in stepped spillways with Λ-shaped step using FLOW-3D. Civ Eng J 3(10):856–867CrossRefGoogle Scholar
  21. Mateos C, Elviro V (2000) Stepped spillways. Design for the transition between the spillway crest and the steps. In: Proceedings of 26 IAHR congress, Hydra, pp 260–265Google Scholar
  22. Meireles I, Matos J (2009) Skimming flow in the nonaerated region of stepped spillways over embankment dams. J Hydraul Eng 135(8):685–689.  https://doi.org/10.1061/(asce)hy.1943-7900.0000047 CrossRefGoogle Scholar
  23. Morovati K, Eghbalzadeh A, Soori S (2016) Study of energy dissipation of pooled stepped spillways. Civ Eng J 2(5):208–220CrossRefGoogle Scholar
  24. Nikseresht AH, Talebbeydokhti N, Rezaei MJ (2013) Numerical simulation of two-phase flow on step-pool spillways. Sci Iran 20(2):222–230Google Scholar
  25. Peyras L, Royet P, Degoutte G (1992) Flow and energy dissipation over stepped gabion weirs. J Hydraul Eng 118(5):707–717.  https://doi.org/10.1061/(asce)0733-9429(1992)118:5(707) CrossRefGoogle Scholar
  26. Pfister M, Hager WH, Minor H-E (2006) Stepped chutes: pre-aeration and spray reduction. Int J Multiph Flow 32(2):269–284.  https://doi.org/10.1016/j.ijmultiphaseflow.2005.10.004 CrossRefzbMATHGoogle Scholar
  27. Pinto MMM, Matos JDSG, dos Santos Viseu MTF (2017) Energy dissipation on stepped spillways with a piano key weir: experimental studyGoogle Scholar
  28. Rahimzadeh H, Maghsoodi R, Sarkardeh H, Tavakkol S (2012) Simulating flow over circular spillways by using different turbulence models. Eng Appl Comput Fluid Mech 6(1):100–109.  https://doi.org/10.1080/19942060.2012.11015406 CrossRefGoogle Scholar
  29. Rice CE, Kadavy KC (1996) Model study of a roller compacted concrete stepped spillway. J Hydraul Eng 122(6):292–297.  https://doi.org/10.1061/(asce)0733-9429(1996)122:6(292) CrossRefGoogle Scholar
  30. Sorensen RM (1985) Stepped spillway hydraulic model investigation. J Hydraul Eng 111(12):1461–1472.  https://doi.org/10.1061/(asce)0733-9429(1985)111:12(1461) CrossRefGoogle Scholar
  31. Tabbara M, Chatila J, Awwad R (2005) Computational simulation of flow over stepped spillways. Comput Struct 83(27):2215–2224.  https://doi.org/10.1016/j.compstruc.2005.04.005 CrossRefGoogle Scholar
  32. Yakhot V, Orszag SA, Thangam S, Gatski TB, Speziale CG (1992) Development of turbulence models for shear flows by a double expansion technique. Phys Fluids A 4(7):1510–1520.  https://doi.org/10.1063/1.858424 MathSciNetCrossRefzbMATHGoogle Scholar

Copyright information

© Shiraz University 2019

Authors and Affiliations

  1. 1.Faculty of Civil EngineeringK.N. Toosi University of TechnologyTehranIran

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