IAHR Document Library

« Back to Library Homepage « Proceedings of the 9th International Symposium on River Sedi...

Velocity Distribution and Sediment Transport in Rivers

Author(s): Shuqing Yang

Linked Author(s): Shuqing Yang

Keywords: Sediment concentration; Reduction of Karman constant; Log-law; Sediment concentration distribution

Abstract: A theoretical analysis of velocity profiles in sediment-laden flows is presented by means of Prandtl-Karman mixing length theorem. The study shows that the upward velocity of liquid-phase caused by settling sediment leads to the invalidity of log-law and Rouse equation. The theoretical analysis takes into account the upward velocity and shows: (1) the mean velocity in sediment-laden flows follows the log-law, but Karman constant reduces in the main flow region; (2) sediment concentration reduces the mixing length of fluid particles; (3) flow resistance reduces with the presence of sediment concentration; and (4) the sediment concentration profile deviates from the well know Rouse equation. The experimental data agree well with the obtained equations that are derived on the basis of non-zero wall velocity. It is found that the wall-normal velocity should not be neglected in density gradient flows because it induces greater wall-normal velocity than that in pure water flows.


Year: 2004

Copyright © 2023 International Association for Hydro-Environment Engineering and Research. All rights reserved. | Terms and Conditions