Compound open-channel flows: effects of transverse currents on the flow structure

The authors wish to thank Fabien Thollet and Alexis Buffet for their technical support, and the anonymous referees for their valuable comments that have helped to improve the paper. This research work was funded by the French National Research Agency under grant N◦ANR-14-CE03-0010 (Flowres ANR project, https://flowres.irstea.fr/en/). Declaration of Interests. The authors report no conflict of interest.

[1]  N. Rivière,et al.  Estimation of the error on the mean velocity and on the Reynolds stress due to a misoriented ADV probe in the horizontal plane: Case of experiments in a compound open-channel , 2013 .

[2]  João Leal,et al.  Turbulent structures, integral length scale and turbulent kinetic energy (TKE) dissipation rate in compound channel flow , 2017 .

[3]  V. Dupuis,et al.  Mixing layer development in compound channel flows with submerged and emergent rigid vegetation over the floodplains , 2017 .

[4]  R. Adrian,et al.  Coherent structures in flow over hydraulic engineering surfaces , 2012 .

[5]  T. Dracos,et al.  Plane turbulent jets in a bounded fluid layer , 1992, Journal of Fluid Mechanics.

[6]  V. Dupuis,et al.  Combined effects of bed friction and emergent cylinder drag in open channel flow , 2016, Environmental Fluid Mechanics.

[7]  W. Uijttewaal,et al.  Effects of shallowness on the development of free-surface mixing layers , 2000 .

[8]  Damon Honnery,et al.  Autocorrelation Functions and the Determination of Integral Length with Reference to Experimental and Numerical Data , 2004 .

[9]  Flow and sediment transport in compound channels : the experiences of Japanese and UK research , 2009 .

[10]  Turbulent flows in straight compound open-channel with a transverse embankment on the floodplain , 2013 .

[11]  K. Shiono,et al.  Complex flow mechanisms in compound meandering channels with overbank flow , 1998, Journal of Fluid Mechanics.

[12]  Lateral bed-roughness variation in shallow open-channel flow with very low submergence , 2019, Environmental Fluid Mechanics.

[13]  G. Constantinescu,et al.  Structure of turbulent flow at a river confluence with momentum and velocity ratios close to 1: Insight provided by an eddy‐resolving numerical simulation , 2011 .

[14]  M. Brocchini,et al.  Horizontal mixing of quasi-uniform straight compound channel flows , 2010, Journal of Fluid Mechanics.

[15]  J. Järvelä,et al.  Turbulence at water-vegetation interface in open channel flow: Experiments with natural-like plants , 2019, Advances in Water Resources.

[16]  D. Knight,et al.  Turbulence measurements in a shear layer region of a compound channel , 1990 .

[17]  P. Ackers.  Flow formulae for straight two-stage channels , 1993 .

[18]  D. Knight,et al.  Flood Plain and Main Channel Flow Interaction , 1983 .

[19]  R. Kraichnan.  Inertial Ranges in Two‐Dimensional Turbulence , 1967 .

[20]  Patrick Tabeling,et al.  Two-dimensional turbulence: a physicist approach , 2002 .

[21]  M. Brocchini,et al.  Lagrangian mixing in straight compound channels , 2011, Journal of Fluid Mechanics.

[22]  Sébastien Proust.  Ecoulements non-uniformes en lits composés : effets de variations de la largeur du lit majeur , 2005 .

[23]  Didier Bousmar,et al.  Energy losses in compound open channels , 2010 .

[24]  Kishanjit Kumar Khatua,et al.  Prediction of discharge in converging and diverging compound channel by gene expression programming , 2019, ISH Journal of Hydraulic Engineering.

[25]  N. Rivière,et al.  Mixing layer and coherent structures in compound channel flows: Effects of transverse flow, velocity ratio, and vertical confinement , 2017 .

[26]  I. Marusic,et al.  Drag forces on a bed particle in open-channel flow: effects of pressure spatial fluctuations and very-large-scale motions , 2019, Journal of Fluid Mechanics.

[27]  Improvement of the Lateral Distribution Method based on the mixing layer theory , 2014 .

[28]  N. Rivière,et al.  Turbulent non-uniform flows in straight compound open-channels , 2013 .

[29]  Vladimir Nikora,et al.  Despiking Acoustic Doppler Velocimeter Data , 2002 .

[30]  Didier Bousmar,et al.  Flow modelling in compound channels : momentum transfer between main channel and prismatic or non-prismatic floodplains , 2002 .

[31]  Didier Bousmar,et al.  Overbank flow in symmetrically narrowing floodplains , 2004 .

[32]  Didier Bousmar,et al.  Flow in compound channel with abrupt floodplain contraction , 2006 .

[33]  R. Mehta.  Effect of velocity ratio on plane mixing layer development: Influence of the splitter plate wake , 1989 .

[34]  V. Dupuis,et al.  Compound channel flow with a longitudinal transition in hydraulic roughness over the floodplains , 2017, Environmental Fluid Mechanics.

[35]  R. Adrian,et al.  Very large-scale motion in the outer layer , 1999 .

[36]  N. Rivière,et al.  Upstream discharge distribution in compound-channel flumes , 2005 .

[37]  S. H. Truong,et al.  Exchange Processes Induced by Large Horizontal Coherent Structures in Floodplain Vegetated Channels , 2019, Water Resources Research.

[38]  G. Batchelor.  Computation of the Energy Spectrum in Homogeneous Two‐Dimensional Turbulence , 1969 .

[39]  I. Nezu,et al.  Turbulent Structure in Compound Open‐Channel Flows , 1991 .

[40]  V. Chu,et al.  Confinement and Bed‐Friction Effects in Shallow Turbulent Mixing Layers , 1988 .

[41]  G. Besio,et al.  Transversal and longitudinal mixing in compound channels , 2012 .

[42]  I. Wygnanski,et al.  The forced mixing layer between parallel streams , 1982, Journal of Fluid Mechanics.

[43]  R. Sellin.  A laboratory investigation into the interaction between the flow in the channel of a river and that over its flood plain , 1964 .

[44]  Macrovortices-induced horizontal mixing in compound channels , 2004 .

[45]  I. Wygnanski,et al.  The two-dimensional mixing region , 1970, Journal of Fluid Mechanics.

[46]  Terry W. Sturm,et al.  Water Surface Profiles in Compound Channel with Multiple Critical Depths , 1996 .

[47]  R. H. J. Sellin,et al.  SERC flood channel facility: skewed flow experiments , 1990 .

[48]  V. Nikora,et al.  Secondary currents and very-large-scale motions in open-channel flow over streamwise ridges , 2020, Journal of Fluid Mechanics.

[49]  Ivan Marusic,et al.  Evidence of very long meandering features in the logarithmic region of turbulent boundary layers , 2007, Journal of Fluid Mechanics.

[50]  D. Knight,et al.  Turbulent open-channel flows with variable depth across the channel , 1991, Journal of Fluid Mechanics.

[51]  Gerard Nicollet,et al.  Écoulements permanents à surface libre en lits composés , 1979 .

[52]  Michael Stewart,et al.  Very-large-scale motions in rough-bed open-channel flow , 2017, Journal of Fluid Mechanics.

[53]  J. A. Battjes,et al.  Momentum Exchange in Straight Uniform Compound Channel Flow , 2005 .

[54]  A. Roshko,et al.  On density effects and large structure in turbulent mixing layers , 1974, Journal of Fluid Mechanics.