Author(s): I. Guymer; K. J. Spence
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Keywords: No Keywords
Abstract: Laboratory experiments have been performed within a compound channel to investigate the transverse mixing of a solute tracer during both in-bank and overbank flows. Attention was focused on the effect of a cross-stream (transverse) depth variation from main channel to flood plain on the transverse variation of the local transverse mixing coefficient. The temporal variation of the longitudinal and transverse velocities and their spatial variation within the cross-section have been measured. The variation of solute concentrations has been quantified in both the near-and mid-field mixing zones. The generalized change of moment method was employed to estimate transverse variations of the transverse mixing coefficient. This shows that assuming a transverse variation of the transverse mixing coefficient of the form of the spatial distribution of Reynolds' stress, reproduces the observed mixing, but that values greater than the eddy viscosity are required to predict the mixing on the floodplain close to the main channel.
Year: 2009