Numerical Simulation of Flow in the USBR II Stilling Basin with Converging Walls and End Steps

Authors

1 Assist. Prof., Dept. of Eng., Faculty of Civil Engineering, Azad University, Khorramabad Branch, Lorestan, Iran

2 Assoc. Prof., Dept. of Water Resources Eng., Faculty of Civil Engineering, University of Tabriz, Iran

3 M.Sc. Student, Dept. of Water Resources Eng., Faculty of Civil Engineering, University of Tabriz, Iran‎

4 Ph.D. Student, Dept. of Water Eng. and Hydraulic Structures, Faculty of Civil Engineering, Semnan University, Semnan, Iran

Abstract

The stilling basins are of the most important energy dissipater structures, and changes in their shape lead to a better ‎hydraulic performance of them. In this study, the impacts of steps at the end of USBR II stilling ‎basin of Nazloo-Chay ‎dam and walls convergence on the pressure, water surface profile, efficiency of ‎hydraulic jump and energy dissipation ‎were investigated. For this purpose, the flow was ‎simulated using the VOF method and RNG turbulent model in ‎the ‎converging stilling basin (with convergence angle of 5◦, 7.5◦, 10◦ and 12.5◦) and discharge rate of 830 m3/s. The ‎numerical model was ‎verified by pressure's experimental data. The results showed that existence end steps and ‎convergence walls led to an increase in tail water depth and prevented hydraulic jump from exhausting out of ‎stilling ‎basin. Also, the convergence walls caused the jump to be submerged contrary to the free jump occurring in ‎stilling basins with parallel walls having free jumps. Convergence Walls had a positive impact on the efficiency of the ‎hydraulic jump. In this study, the converging stilling basin with 5◦ convergence angel gave a great performance, and the ‎efficiency increased by 136% in comparison to stilling basin with parallel walls. The comparison of the ‎results of energy ‎dissipation for different sections of stilling basin at different flow depths ‎demonstrated that the maximum energy ‎dissipation occurred in the depths between 20-30% of flow depth. These results may be considered for improving the ‎stilling basins design.‎

Keywords

References

Abrishami J and Esmaeili K, 2000. Hydraulic jump over negative slopes with negative steps. Journal of Advanced Materials in Engineering 19(2): 97-110 (In Persian with English abstract).
Abrishami J and Esmaieli K, 2001. Determination of the relationship between before- and after-jump depths and step height in order to control hydraulic jump over pools with a positive or negative slope. International Conference on Hydraulic Structures of Civil Engineering, Shahid Bahonar University of Kerman (In Persian with English abstract).
Anonymous, 2006. Hydraulic Model of Nazloochai Dam Stilling Basin, Water Research Institute, Tehran, Iran (In Persian).
Anonymous, 2008. Hydraulic Model of Lower Discharge of Gotvand upper Dam. Water Research Institute. Tehran, Iran (In Persian).
Anonymous, 2008. Excellence in Flow Modeling Software, V 9.3‎, Flow Science, Inc., Santa Fe, N.M.
‎‎Arabhabhirama A and Abella AU, 1971. Hydraulic jump within gradually expanding channel. Journal ‎of Hydraulic Engineering American Society of Civil Engineers 97(1):31-42.‎
‎Babaali H, Shamsai A and Vosoughifar H, 2015. Computational modeling of the hydraulic jump in the ‎stilling basin with convergence walls using CFD codes. Arabian Journal Science Engineering 40(2):381–395.‎
Babaali HR, Soori N, Soori S, Mojtahedi AR and Hamedi AM, 2018. Static pressure estimation on converging USBR II Stilling Basin: Numerical Approach. International Journal of Science and Engineering Investigations 7(79): 2251-8843.
Bakhtiari M, and Kashafipour M, 2008. Investigation of hydraulic properties of jumping parameters in divergent sections. 4th National Congress of Civil Engineering, University of Tehran, Tehran, Iran (In Persian with English abstract).
‎Bayon A, Valero D, García-Bartual R, Valles-Moran FJ and Amparo Lopez-Jimenez P, 2016. Performance assessment of OpenFOAM and Flow-3D in the numerical modeling of a low Reynolds ‎number hydraulic jump. Environmental Modeling and Software 80:322-335.‎
Chanson H, 2015. Energy Dissipation in Hydraulic Structures. IAHR Monographs, CRC Press/Balkema, Taylor and Francis Group.
‎Davidson P, 2015. Turbulence: An Introduction for Scientists and Engineers. Oxford University Press. ‎USA.‎
Esmaili K and Abrishami J, 2000. Hydraulic jump over negative slopes with negative steps. Journal of Advanced Materials in Engineering 19(2): 97-110 (In Persian with English abstract).
Esmaili M, 2003. Study of the properties of diverging hydraulic leakage in a trapezoidal relaxation pool. M.Sc. thesis, Faculty of Agriculture, University of Tehran (In Persian with English abstract).
Felder S and Chanson H, 2013. Aeration, flow instabilities, and residual energy on pooled stepped ‎spillways of embankment dams. Journal of Irrigation Drainage Engineering 139(10):880–887.‎    
‎Forster JW and Skrinde RA, 1950. Control of the hydraulic jump by sill. Transaction of American Society of Civil Engineers 115(2415):988-991.‎
‎Gamal HE, Abdelazim MA, Neveen BA and Ahmed MI, 2016. Effect of end step ‎shape in the performance of stilling basins downstream radial gates. Journal of Scientific Research and ‎Reports 9(1):1-9.‎
‎Ippen AT, 1951. Mechanics of supercritical flow. Transaction of American Society of Civil Engineer 116:268-295.‎
Kassi Kozani A, 2010. Experimental study of the properties of diverging hydraulic jumps in a stilling basin with a reverse slope. M.Sc. thesis, Faculty of Agriculture, University of Tehran (In Persian with English abstract).
‎Khlifa AM and McCorquodale AM, 1980. Submerged radial hydraulic jump. Journal of Hydraulic ‎Division, American Society of Civil Engineers 106(HY3):355-367.‎
Minaei Gigloo A, Ghodsian M and Mehraein M, 2016. Experimental investigation of hydraulic jump in stilling basin with stepped sill. Modares Civil Engineering 16(1)­:146-156 (In Persian with English abstract).
‎Omid MH, Esmaeili Varaki M and Narayanan R, 2007. Gradually expanding hydraulic jump in a ‎trapezoidal channel. Journal of Hydraulic Research (4):512–518.‎
‎Pirestani MR, Razmkhah A and Ghobadi F, 2012. Effect of convergence walls on energy ‎dissipation in stilling basin by physical modelling. International Journal of Thermal and Fluid Science 1(1):1-10.‎
Sahebbi F, Esmaili M, Navabian M and Amiri Z, 2012. Economic evaluation of the effect of divergence of stilling basin walls on changes in construction costs. 11th Iranian Hydraulic Conference. November 18-18, Urmia University, Urmia, Iran (In Persian with English abstract).
Shojaeian Z, Hosseinzadeh Delir A, Forsadizadeh D and Salmasi F, 2011. Investigation of hydraulic jump properties in divergent rectangular sections with inverse slope. Water and Soil Science- University of Tabriz, 21(3): 50-60 (In Persian with English abstract).
Soori S, Babaali HR and Soori N, 2017. An optimal design of the inlet and outlet obstacles at USBR II stilling basin. International Journal of Science and Engineering Applications 6(5):134-142.
‎‎ ‎Wang K, Jin S and Liu G, 2009. Numerical modeling of free-surface flows with bottom and surface-‎layer pressure treatment. Journal of Hydrodynamics 21(3):352-359. ‎
‎Wu JH and Wan-Zheng AI, 2010. Flows through energy dissipaters with sudden reduction and ‎sudden enlargement forms. Journal of Hydrodynamics 22(3):360-365.‎
Water and Soil Science
Volume 31, Issue 1
March 2021
Pages 59-73

Files

Share

How to cite

Statistics