Author(s): D. Bousmar; M. Omran; S. Atabay; D. W. Knight
Linked Author(s): Didier Bousmar
Keywords: No Keywords
Abstract: The flow structure in meandering compound channels has already been extensively described in the literature. Cross-over flows have been identified, and the inversion of the helical currents in the bends has been highlighted for some flow conditions. On the other hand, bed shear stress and flow resistance were poorly investigated. The purpose of this paper is therefore to re-analyse some of the Flood Channel Facility series B data, dealing with rigid bed meandering geometries. First, the bed shear stress distribution is analysed, highlighting the areas with fast velocities on the floodplains, near the ejections zones of the main-channel. Using the velocity data, local, zonal and global friction factors are computed and analysed with comparison to the flow structure. Lastly, apparent shear stresses at the interface and momentum balance are also computed, to quantify the momentum transfer between subsections. The analyses provide improved estimates of friction factors across and along the channel. It is expected that these results can help further improvement and validation of 1D and 2D models, getting closer to the actual flow physics.
Year: 2009