Influence of the secondary motions on pollutant mixing in a meandering open channel flow

  • Ignacio J. Moncho-Esteve
  • Frederik Folke
  • Manuel García-Villalba
  • Guillermo Palau-Salvador
Original Article

DOI: 10.1007/s10652-017-9513-4

Cite this article as:
Moncho-Esteve, I.J., Folke, F., García-Villalba, M. et al. Environ Fluid Mech (2017). doi:10.1007/s10652-017-9513-4
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Abstract

This paper presents large eddy simulation of turbulent flow in a meandering open channel with smooth wall and rectangular cross-section. The Reynolds number based on the channel height is 40,000 and the aspect ratio of the cross-section is 4.48. The depth-averaged mean stream-wise velocity agree well to experimental measurements. In this specific case, two interacting cells are formed that swap from one bend to the other. Transport and mixing of a pollutant is analysed using three different positions of release, e.g. on the inner bank, on the outer bank and on the centre of the cross section. The obtained depth-average mean concentration profiles are reasonably consistent with available experimental data. The role of the secondary motions in the mixing processes is the main focus of the discussion. It is found that the mixing when the scalar is released on the centre of the cross-section is stronger and faster than the mixing of the scalar released on the sides. When the position of release is close to a bank side, the mixing is weaker and a clear concentration of scalar close to the corresponding side-wall can be observed in both cases.

Keywords

Large Eddy simulation Pollutant mixing River flow Turbulence 

Copyright information

© Springer Science+Business Media Dordrecht 2017

Authors and Affiliations

  • Ignacio J. Moncho-Esteve
    • 1
  • Frederik Folke
    • 2
    • 4
  • Manuel García-Villalba
    • 3
  • Guillermo Palau-Salvador
    • 1
  1. 1.Hydraulic Division, Department of Rural and Agrifood EngineeringUniversitat Politècnica de ValènciaValenciaSpain
  2. 2.Institute for HydromechanicsKarlsruhe Institute of TechnologyKarlsruheGermany
  3. 3.Bioengineering and Aerospace Engineering DepartmentUniversidad Carlos III de MadridLeganésSpain
  4. 4.Federal Waterways Engineering and Research Institute (BAW)KarlsruheGermany