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Article information
2019 , Volume 24, ¹ 6, p.99-107
Potapov I.I., Snigur K.S., Tsoy G.I.
On the modelling of turbulent flow over low-angle sand dunes
Purpose. The aim of the paper is the development of mathematical models describing a turbulent river flow along gently sloping dunes and allowing estimation of the contribution of gently sloping dunes on the flow hydraulic resistance. Methodology. A quasi-hydrodynamic form of the classical RANS equations are used for describing the hydrodynamic flow. The standard k-e model is used for the turbulence viscosity while the equations have been transformed to the quasi-hydrodynamic form. A wall functions method is used for describing the flow near solid channel wall. Results. A new mathematical model for the problem of turbulent flow in a pressure channel with low-angle dunes is proposed. An algorithm for solving the problem is proposed. It is based on the control volume method and the finite element method. The problem of the turbulent flow over 6 fixed low-angle sand dunes is solved numerically. Numerical solutions are obtained with four different wall functions. A comparative analysis of the obtained solutions with the experimental data is carried out. Findings. It is shown that the proposed mathematical model describes the turbulent flow over low-angle dunes qualitatively and quantitatively. The solution obtained with the Volkov wall function provides the best agreement with the experiment. It is found out that the bed shear stress obtained in the near-wall computational cell by the wall functions method does not qualitatively agree with the experimental data for all considered wall functions. At the same time, the shear stress obtained in the next calculation cell agrees with the experimental data qualitatively and quantitatively. The average relative error of the shear stress obtained with the Volkov wall function is 6.84%.
[full text] [link to elibrary.ru]
Keywords: hydrodynamics, turbulent flow, low-angle dunes, quasi-hydrodynamic equations, wall functions, mathematical modeling
doi: 10.25743/ICT.2019.24.6.012.
Author(s):
Potapov Igor Ivanovich
Dr.
Position: General Scientist
Office: Computer center of Far East Branch of the Russian Academy of Sciences
Address: 680000, Russia, Khabarovsk, 65, Kim U Chena street
Phone Office: (4212) 22-72-67
E-mail: potapov2i@gmail.com
Snigur Kseniya Sergeevna
PhD.
Position: Senior Research Scientist
Office: Computing Center of the Far-Eastern Branch of Russian Academy of Sciences
Address: 680021, Russia, Khabarovsk, Yashina street
Phone Office: (4212) 22-72-67
E-mail: snigur.ks@ccfebras.ru
Tsoy Georgiy Ilich
Position: Junior Research Scientist
Office: Computing Center of the Far-Eastern Branch of Russian Academy of Sciences
Address: 680021, Russia, Khabarovsk, Yashina street
Phone Office: (4212) 70-39-12
E-mail: tsoy.dv@mail.ru
References:
[1] Coleman, S.E., Nikora, V.I. Fluvial dunes: Initiation, characterization, flow structure. Earth Surface Processes and Landforms. 2011; 36(1):39–57.
[2] Bradley, R.W., Venditti, J.G., Kostaschuk, R.A., Church, M., Hendershot, M., Allison, M.A. Flow and sediment suspension events over low-angle dunes: Fraser Estuary, Canada. . Journal of geophysical research: Earth surface. 2013; (108):1693–1709. DOI:10.1002/jgrf.20118.
[3] Cisneros, J., Best, J. Low angle dunes in big rivers morphology occurrence and speculations on their origin. Marine and River Dune Dynamics Conf. Papers (MARIDV). UK, North Wales; 2016: 37–40.
[4] Best, J.L., Kostaschuk, R.A. An experimental study of turbulent flow over a low-angle dune. Journal of Geophysical Research. 2002; 107(C9):3135. DOI:10.1029/2000JC000294.
[5] Shugar, D.H., Kostaschuk, R.A., Best, J.L., Parsons, D.R., Lane, S.N., Orfeo, O., Hardy, R.J. On the relationship between flow and suspended sediment transport over the crest of a sand dune, Rio Parana, Argentina. Sedimentology. 2010; 57(1):252– 272. DOI:10.1111/j.1365-3091.2009.01110.x.
[6] Paarlberg, A.J., Dohmen-Janssen, C.M., Hulscher, S.J.M.H., Termes, P., Schielen, R. Modelling the effect of time-dependent river dune evolution on bed roughness and stage. Earth Surface Processes and Landforms. 2010; 35(15):1854–1866. DOI:10.1002/esp.2074.
[7] Huthoff, F. Theory for flow resistance caused by submerged roughness elements. Journal of Hydraulic Research. 2012; 50(1):10–17. DOI:0.1080/00221686.2011.636635.
[8] Kwoll, E., Venditti, J.G., Bradley, R.W., Winter, C. Flow structure and resistance over subaqueous high- and low-angle dunes. . Journal of geophysical research: Earth surface. 2016; (121):545–564.
[9] Elizarova, T.G., Nikol’skii, P.N. Numerical simulation of the laminar-turbulent transition in the flow over a backward-facing step. Moscow State Univ. Bulletin. Ser. 3. Physics, Astronomy. 2007; 62(4):216–220.
[10] Wilcox, D.C. Turbulence Modeling for CFD. Second edition. Anaheim: DCW Industries; 1998: 174.
[11] Volkov, K.N. Near-wall modeling in computations of turbulent flows on unstructured grids. Thermophysics and Aeromechanics. 2007; 14(1):107–123.
[12] Stigler, J. Introduction of the analytical turbulent velocity profile between two parallel plates. 18th Intern. Conf. Engineering Mechanics. 2012. Czech Republic. Paper No. 148. 2012:1343–1352.
[13] Jamil, M.M., Adamu, M.I., Ibrahim, T.R, Hashim, G.A. Numerical study of separation length of flow through rectangular channel with baffle plates. Journal of Advanced Research Design. 2015; 7(1):19–33.
[14] Connor, J.J., Brebbia, C.A. Finite Element Techniques for Fluid Flow. London: NewnesButterworth; 1976:317.
[15] Snegirev, À.Yu. Vysokoproizvoditel'nye vychisleniya v tekhnicheskoy fizike. Chislennoe modelirovanie turbulentnykh techeniy. Uchebnoe posobie [High performance computing in technical physics. Numerical simulation of turbulent flows]. SPb.: Izdatel'stvo Politekhnicheskogo un-ta; 2009:143. (In Russ.)
Bibliography link:
Potapov I.I., Snigur K.S., Tsoy G.I. On the modelling of turbulent flow over low-angle sand dunes // Computational technologies. 2019. V. 24. ¹ 6. P. 99-107
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