A Study of the Formation of Velocity Counter Lines and Secondary (Spiral) Flows in Different Cross Sections of Divergent, Convergent and Uniform Arcs

A. Liaghat, N. Tavanpour

Abstract


The mechanical properties of flow are very complex in channel arcs. Therefore, dynamic numerical models of fluids are considered effective tools in predicting such flow fields. In this study, the numerical model was validated by the measures of a uniform U-shaped arc with a width of 0.6 meter. Then two similar U shaped arcs, divergent and convergent, were simulated by a three-dimensional numerical model with variable widths from 0.6 to 0.75 meters and 0.6 to 0.45 meters. Validating the numerical model by measured data in the uniform 180-degree arc showed that the model can simulate the flow field in the uniform arc very well. Results regarding several parameters such as rout of maximum velocity, maximum velocity line, water level variations, power of spiral flow, existence of a rotating cell are stated and discussed.


Keywords


Arc; Secondary flow (spiral); Velocity Counters; SSIIM three-dimensional numerical model

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References


N. Rüther, Computational Fluid Dynamics in Fluvial Sedimentation Engineering. Ph. D. Dissertation, Norwegian University of Science and Technology, Trondheim, Norway, 2006

V. T. Chow, Open Channel Hydraulics, McGraw-Hill, New York, 1959

C. E. Mockmore, “Flow around bends in stable channels”, Transactions of the American Society of Civil Engineers, Vol. 109, No. 1, pp. 593-618, 1994

I. L. Rozovskii, Flow of Water in Bend of Open Channel, Institute of Hydrology and Hydraulic Engineering, Academy of Sciences of the Ukrainian SSR, Kiev, 1957

E. Mosonyi, W. Gotz, Secondary currents in subsequent model bends. Proceedings of the International Association for Hydraulic Research International Symposium on River Mechanics, Asian Institute of Technology, Bangkok, 1973

M. A. Leschziner, W. Rodi, “Calculation of strongly curved open channel flow”, Journal of the Hydraulic Division, Vol. 105, No.10, pp. 1297-1314, 1979

H. C. Lien, J. C. Yang, K. C. Yeh, T. Y. Hsieh, “Bend-flow simulation using 2D depth-averaged model”, Journal of Hydraulic Engineering, Vol. 125, No. 10, pp. 1097-1108, 1999

R. Booij, “Measurements and large eddy simulations in some curved flumes”, Journal of Turbulence, Vol. 4, No. 1, pp. 8-16, 2003

N. R. B. Olsen, A Three-Dimensional Numerical Model for Simulation of Sediment Movements in Water Intakes with Multiblock Option, Department of Hydraulic and Environmental Engineering, Norwegian University of Science and Technology, Trondheim, Norway, 2006

S. L. Huang, Y. F. Jia, S. Y. Wang, “Numerical Modeling of Suspended Sediment Transport in Channel Bends”, Journal of Hydrodynamics, Vol. 18, No. 4, pp. 411-417. 2006

L. Begnudelli, A. Valiani, B. F. Sanders, “A balanced treatment of secondary currents, turbulence and dispersion in a depth-integrated hydrodynamic and bed deformation model for channel bends”, Journal of Advances in Water Resources, Vol. 33, No. 1, pp. 17–33, 2010

M. Naji Abhari, M. Ghodsian, M. Vaghefi, N. Panahpur, “Experimental and numerical simulation of flow in a 90° bend”, Journal of Flow Measurement and Instrumentation, Vol. 21, No. 3, pp. 292-298, 2010

B. E. Launder, D. B. Spalding, “The numerical computation of turbulent flows”, Computer Methods in Applied Mechanics and Engineering, Vol. 3, No. 2, pp. 269-289, 1974

H. Schlichting, Boundary Layer Theory. 7th ed. New York: McGraw-Hill, 1979

M. Pirestani, Study of Flow and Scouring Patterns at Intake Entrance of Curved Canals, Ph. D. Dissertation, Azad Islamic University, Tehran, Iran, 2004




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