Energy Dissipation of Converged Ski-jump Buckets by using Dividing Wall

Document Type : Research Article

Authors

1 Civil Engineering Department, Sistan and Baluchastan University, Sistan and Baluchastan, Iran.

2 Civil Engineering Department, Isfahan University of Technology, Isfahan, Iran.

Abstract

Ski-jump bucket spillway is one of the energy dissipation structures applied at downstream of spillways or bottom outlets. In this study, the effect of the convergence angle of the ski-jump bucket on the flow energy dissipation was experimentally investigated and the results were compared with the conventional bucket model. For this purpose, four convergence angles of 10, 20, 30 and 40 degrees were created using deflectors in the bucket. The effect of adding a dividing wall, in two modes of bucket splitter wall (BSW) and full separator wall (FSW), on the conventional and convergent buckets were investigated. The results showed that the flip buckets dissipated about 60 to 65 percent of their energy. At a 20-degree convergence angle, the energy dissipation of the flow increased by about 5 percent, however, at a 30-degree convergence angle, the energy dissipation decreased by about 15 percent. In general, the energy dissipation decreases by increasing the flow discharge. Adding a dividing wall to the bucket does not have a significant effect on energy dissipation, although adding a separator wall to a converged bucket eliminates the effect of reduction in the energy dissipation due to convergence of the bucket. By mounting the dividing wall on the bucket, a local disturbance is created in the flow pattern, however, the resulting loss is not significant compared to the energy dissipation caused by the jet colliding with the bottom of the stilling basin. Whereas full separator wall (FSW) divides the bucket into two parts and it doesn't cause major disruption to the flow pattern.
 

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[1]] H. Chanson, The hydraulics of stepped chutes and spillways, 2002.
[2] W.H. Hager, Energy dissipators and hydraulic jump, Springer Science & Business Media, 2013.
[3] A. Parsaie, A.H. Haghiabi, The Hydraulic Investigation of Circular Crested Stepped Spillway, Flow Measurement and Instrumentation,  (2019) 101624.
[4] A. Parsaie, A.H. Haghiabi, M. Saneie, H. Torabi, Applications of soft computing techniques for prediction of energy dissipation on stepped spillways, Neural Computing and Applications, 29(12) (2018) 1393-1409.
[5] A. Lauria, G. Alfonsi, Numerical Investigation of Ski Jump Hydraulics, Journal of Hydraulic Engineering, 146(4) (2020) 04020012.
[6] S.H. Chen, Hydraulic Structures, Springer Berlin Heidelberg, 2015.
[7] V. Heller, W.H. Hager, H.-E. Minor, Ski Jump Hydraulics, Journal of Hydraulic Engineering, 131(5) (2005) 347-355.
[8] B.o.I. Standards, Criteria of hydraulic design of bucket type energy dissipators, in, Bureau of Indian Standards New Delhi,, India, 1985.
[9] R. Juon, W.H. Hager, Flip Bucket without and with Deflectors, Journal of Hydraulic Engineering, 126(11) (2000) 837-845.
[10] D. Vischer, W. Hager, Energy dissipators, Oceanographic Literature Review, 1(43) (1996) 87.
[11] A. Larese, R. Rossi, E. Oñate, S. Idelsohn, Validation of the particle finite element method (PFEM) for simulation of free surface flows, Engineering Computations,  (2008).
[12] R. Steiner, V. Heller, W.H. Hager, H.-E. Minor, Deflector ski jump hydraulics, Journal of Hydraulic Engineering, 134(5) (2008) 562-571.
[13] T. Zhang, H. Chen, W. Xu, Allotypic hybrid type flip bucket. II: Effect of contraction ratio on hydraulic characteristics and local scour, J. Hydroelec. Eng, 32 (2013) 140-146.
[14] J. Deng, W. Wei, Z. Tian, F. Zhang, Design of A Streamwise-Lateral Ski-Jump Flow Discharge Spillway, Water, 10(11) (2018) 1585.
[15] J. Kerman-Nejad, M. Fathi-Moghadam, B. Lashkarara, S. Haghighipour, Dynamic pressure of flip bucket jets, World applied sciences journal, 12(8) (2011) 1165-1171.
[16] M. Sadeghi Askari, H. Mousavi, M. Ghomeshi, Investigation the Effect of Wedge-Shaped Deflector Length and Angle in Energy Dissipation on the Flip Bucket Spillway, Journal of Irrigation Sciences and Engineering (JISE), 39(4) (2017) 225 - 235.
[17] M. Sadeghi Askari, M. Ghomeshi, Energy Dissipation due to Deflector in Simple Flip Bucket Spillway and Flip Bucket Spillway with Approach Channel, Water and Soil Science, 23(4) (2014) 131-140.
[18] M. Sadeghi Askari, M. GHomeshi, Energy dissipation due to deflector in simple flip bucket spillway and flip bucket spillway with approach channel, Iranian Water Research Journal, 23(4) (2013) 131-141.
[19] M. Kakeshpour, M. Pirestani, M. Zakeri Niri, Numerical Simulation of Jet Flow and Investigation Effect of Triangular Shape of Bucket, and Gate Opening Ratio on Flip Bucket Jet Flow Characters, Water and Soil Science, 26(1-1) (2016) 291-303.
[20] M. Kakeshpour, M. Pirestani, M. Zakeri Niri, Numerical simulation of overflow with consider of shape of flip bucket in chute spillway, Journal of Water and Soil Conservation, 23(5) (2016) 223-237.
[21] M. Omidvarinia, S. Mousavijahromi, Comparative Analysis of energy Losses in the Traditional and Triangular Flip Buckets, Irrigation Sciences and Engineering, 37(1) (2014) 133-142.
[22] S. Farzin, H. Karami, M. Fazlollahnejad, S. Nayyer, Numerical Modeling and Analysis of Flow Hydrodynamics in Flip Bucket and Approach Channel, Iranian Jornal of Watershed Management Science&Engineering, 13(41) (2018) 41-50.