Water Science and Engineering 2011, 4(3) 270-283 DOI:   10.3882/j.issn.1674-2370.2011.03.004  ISSN: 1674-2370 CN: 32-1785/TV

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Keywords
 flow pattern
numerical simulation
convergent 180°
bend
SSIIM 3-D model
Authors
RASOOL -ghobadian
PubMed
Article by Rasool,.G

Simulation of subcritical flow pattern in 180o  uniform and convergent open-channel bends using SSIIM 3-D model

Rasool GHOBADIAN*1, Kamran MOHAMMADI2

1. Department of Water Engineering, Razi University, Kermanshah 6715685438, Iran 
2. Department of Water Engineering, University of Tabriz, Tabriz 5166616471, Iran

Abstract

In meandering rivers, the flow pattern is highly complex, with specific characteristics at bends that are not observed along straight paths. A numerical model can be effectively used to predict such flow fields. Since river bends are not uniform–some are divergent and others convergent–in this study, after the SSIIM 3-D model was calibrated using the result of measurements along a uniform 180° bend with a width of 0.6 m, a similar but convergent 180° bend, 0.6 m to 0.45 m wide, was simulated using the SSIIM 3-D numerical model. Flow characteristics of the convergent 180° bend, including lengthwise and vertical velocity profiles, primary and secondary flows, lengthwise and widthwise slopes of the water surface, and the helical flow strength, were compared with those of the uniform 180° bend. The verification results of the model show that the numerical model can effectively simulate the flow field in the uniform bend. In addition, this research indicates that, in a convergent channel, the maximum velocity path at a plane near the water surface crosses the channel’s centerline at about a 30° to 40° cross-section, while in the uniform bend, this occurs at about the 50° cross-section. The varying range of the water surface elevation is wider in the convergent channel than in the uniform one, and the strength of the helical flow is generally greater in the uniform channel than in the convergent one. Also, unlike the uniform bend, the convergent bend exhibits no rotational cell against the main direction of secondary flow rotation at the 135° cross-section.

Keywords  flow pattern   numerical simulation   convergent 180°   bend   SSIIM 3-D model  
Received 2011-03-17 Revised 2011-08-29 Online: 2011-09-30 
DOI: 10.3882/j.issn.1674-2370.2011.03.004
Fund:
Corresponding Authors: Rasool GHOBADIAN
Email: rsghobadian@gmail.com
About author:

References:

Booij, R. 2003. Measurements and large eddy simulations in some curved flumes. Journal of Turbulence, 4(1), 8-16. [doi:10.1088/1468-5248/4/1/008]
Chow, V. T. 1959. Open Channel Hydraulics. NewYork: McGraw-Hill.
Ghobadian, R., Mohammadi, K., and Hossinzade, D. A. 2010. Numerical simulation and comparison of flow characteristics in 180º divergent and uniform open-channel bends using experimental data. Journal of Irrigation Science and Engineering, 33(1), 59-75. (in Persian)
Launder, B. E., and Spalding, D. B. 1974. The numerical computation of turbulent flows. Computer Methods in Applied Mechanics and Engineering, 3(2), 269-289. [doi:10.1016/0045-7825(74)90029-2]
Leschziner, M. A., and Rodi, W. 1979. Calculation of strongly curved open channel flow. Journal of the Hydraulic Division, 105(10), 1297-1314.
Lien, H. C., Yang, J. C., Yeh, K. C., and Hsieh, T. Y. 1999. Bend-flow simulation using 2D depth-averaged model. Journal of Hydraulic Engineering, 125(10), 1097-1108. [doi:10.1061/(ASCE)0733-9429 (1999)125:10(1097)]
Mansuri, A. R. 2006. 3-D Numerical Simulation of Bed Changes in 180 Degree Bends. M. S. Dissertation. Tehran: Tarbyat Modares University. (in Persian)
Mockmore, C. E. 1944. Flow around bends in stable channels. Transactions of the American Society of Civil Engineers, 109, 593-618.
Mosonyi, E., and Gotz, W. 1973. Secondary currents in subsequent model bends. Proceedings of the International Association for Hydraulic Research International Symposium on River Mechanics, 191-201. Bangkok: Asian Institute of Technology.
Olsen, N. R. B. 2006. A Three-Dimensional Numerical Model for Simulation of Sediment Movements in Water Intakes with Multiblock Option. Trondheim: Department of Hydraulic and Environmental Engineering, the Norwegian University of Science and Technology.
Pirestani, M. 2004. Study of Flow and Scouring Patterns at Intake Entrance of Curved Canals. Ph. D. Dissertation. Tehran: Azad Islamic University.
Rozovskii, I. L. 1957. Flow of Water in Bend of Open Channel. Kiev: Institute of Hydrology and Hydraulic Engineering, Academy of Sciences of the Ukrainian SSR.
Rüther, N. 2006. Computational Fluid Dynamics in Fluvial Sedimentation Engineering. Ph. D. Dissertation. Trondheim: Norwegian University of Science and Technology.
Schlichting, H. 1979. Boundary Layer Theory. 7th ed. New York: McGraw-Hill.

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