Comparison of Subcritical and Supercritical Flow Characteristics in U-shaped Channels Along Submerged and Non-Submerged Side Weir

Authors

1 M.Sc. of Water Engineering, Dept. of Civil Engineering, Razi University, Kermanshah, Iran

2 Asso. Prof., Dept. of Water Engineering, Kermanshah Branch, Islamic Azad University, Kermanshah, Iran

3 Assis. Prof., Dept. of Architecture, Science and Research Branch, Islamic Azad University, Tehran, Iran

Abstract

Generally, side weirs are used for regulating and controlling the flow in the main channels. U-shaped channels are used as transition structure from rectangular to circular cross-section in sewage systems. This study presented a flow field simulation in the U-shaped channels along a side weir using FLOW-3D software, the RNG k-ε turbulence model and volume of fluid (VOF) scheme under the subcritical and supercritical flow conditions. The good agreement was obtained between the results of the numerical simulation and the experimental measurements for both flow regimes. For example, the root mean square error for subcritical and supercritical flow regimes was computed as 2.86% and 2.21%, respectively. In subcritical flow regime, a secondary flow created in the main channel which developed toward the downstream. The lateral flow increased from the beginning of the side weir toward the downstream end of the weir under supercritical flow regime. The effects of the side weirs submergence were investigated on the flow pattern in the main channel too. The maximum transverse velocity almost happened at the middle of the submerged weir length

Keywords

References

Aydin MC, 2012. CFD simulation of free-surface flow over triangular labyrinth side weir. Adv. Eng. Soft. 45, 159-166.
Aydin MC and Emiroglu ME, 2013. Determination of capacity of labyrinth side weir by CFD. Flow. Meas. Instrument. 29, 1-8.
Azimi H and Shabanlou S, 2016. Numerical simulation of flow free surface and field in circular channel along the sideweir in subcritical flow conditions. Water and Soil Science-University of Tabriz. 26(1-1): 225-238.
Azimi H, Shabanlou S, Ebtehaj I and Bonakdari, H, 2016. Discharge coefficient of rectangular side weirs on circular channels. Inter. J. Nonl. Sci. Num. Sim. 17(7-8), 391-399.
Azimi H, Shabanlou S and Salimi MS, 2014. Free surface and velocity field in a circular channel along the side weir in supercritical flow conditions. Flow. Meas. Instrument. 38, 108-115.
Azimi H and Shabanlou S, 2017. Numerical study of the effect of the bed slope change of circular channel on supercritical flow along the side weir. Water and Soil Science-University of Tabriz. 27(3): 53-64.
Bagheri S and Heidarpour M, 2012. Characteristics of Flow over Rectangular Sharp-Crested Side Weirs. J. Irrig. Drain. Eng. 138, 541-547.
FLOW-3D Version 10.0 [Computer Software]. Flow Science, Santa Fe.NM.
Ghodsian M, 2003. Supercritical Flow over a Rectangular Side Weir. Can. J. Civil Eng. 30, 596-600.
Hager WH, 1994. Supercritical Flow in Circular-Shaped Side Weir. J. Irrig. Drain. Eng. 120, 1-12.
Kaya N, Emiroglu ME and Agaccioglu H, 2011. Discharge coefficient of a semi-elliptical side weir in subcritical flow. Flow. Meas. Instrument. 22, 25-32.
Mizumura K, Yamasaka M and Adachi J, 2003. Side Outflow from Supercritical Channel Flow. J. Hydraulic Eng. 129, 769-776.
Neary VS and Odgaard AJ, 1993. Three-dimensional flow structure at open channel diversions. J. Hydraulic Eng. 119(11), 1224-1230.
Neary VS and Odgaard AJ, 1995. Closure to Three-Dimensional Flow Structure at Open Channel Diversions. J. Hydraulic Eng. 121(1), 88–90.
Novak G, Kozelj D, Steinman F and Bajcar T, 2013. Study of flow at side weir in narrow flume using visualization techniques. Flow. Meas. Instrument. 29, 45-51.
Oliveto G, Biggiero V and Fiorentino M, 2001. Hydraulic Features of Supercritical Flow along Prismatic Side Weirs. J. Hydraulic Res, 39, 73-82.
Rosier B, 2007. Interactions of side weir overflow with bed-load transport and bed morphology in a channel. PhD Thesis, EPFL University, Lausanne, Switzerland.
Uyumaz A and Muslu Y, 1985. Flow over side weirs in circular channels. J. Hydraulic Eng. 111, 144-160.
Uyumaz A, 1997. Side weir in U-shaped channels. J. Hydraulic Eng. 123, 639-646.
Vatankhah AR, 2013. Water surface profiles along a rectangular side weir in a U-shaped channel. J. Hydrologic. Eng. 18, 595-602.
Venutelli M, 2008. Method of solution of nonuniform flow with the presence of rectangular side weir. J. Irrig. Drain. Eng. 134, 840-846.
Water and Soil Science
Volume 28, Issue 4
January 2019
Pages 69-81

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