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

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.

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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 279–286

    Google 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

    Article  Google 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

    Article  Google 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

    Article  Google 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)

    Article  Google 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

    Article  Google 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

    Article  Google Scholar 

  8. Chanson H (2002) Hydraulics of stepped chutes and spillways. CRC Press, Boca Raton

    Google 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)

    Article  Google 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

    Article  MATH  Google 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)

    Article  Google 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

    Article  Google Scholar 

  13. Falvey HT (1990) Cavitation in chutes and spillways. US Department of the Interior, Bureau of Reclamation

  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

    Article  Google 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):426–437

    Article  Google Scholar 

  16. Hirt CW, Nichols B (1988) Flow-3D user’s manual. Flow Science Inc, Santa Fe, p 107

    Google 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

    Article  Google Scholar 

  18. Javeh Dam hydraulic studies, Final Report (2011) Iran Water Research Institute, Tehran, Iran

  19. Liao HS, Wu CG (1995) Numerical model of stepped spillway overflow. In: Proceedings of 2nd international conference on hydro-science and engineering

  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):856–867

    Article  Google 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 260–265

  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

    Article  Google Scholar 

  23. Morovati K, Eghbalzadeh A, Soori S (2016) Study of energy dissipation of pooled stepped spillways. Civ Eng J 2(5):208–220

    Article  Google Scholar 

  24. Nikseresht AH, Talebbeydokhti N, Rezaei MJ (2013) Numerical simulation of two-phase flow on step-pool spillways. Sci Iran 20(2):222–230

    Google 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)

    Article  Google 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

    Article  MATH  Google Scholar 

  27. Pinto MMM, Matos JDSG, dos Santos Viseu MTF (2017) Energy dissipation on stepped spillways with a piano key weir: experimental study

  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

    Article  Google 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)

    Article  Google 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)

    Article  Google 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

    Article  Google 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

    MathSciNet  Article  MATH  Google Scholar 

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Correspondence to Kazem Dalili Khanghah.

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Dalili Khanghah, K., Kavianpour, M.R. 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. Iran J Sci Technol Trans Civ Eng 44, 1247–1254 (2020). https://doi.org/10.1007/s40996-019-00313-8

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Keywords

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