Longitudinal Dispersion for Flow over Rough Beds
- 1 April 1976
- journal article
- Published by American Society of Civil Engineers (ASCE) in Journal of the Hydraulics Division
- Vol. 102 (4) , 483-498
- https://doi.org/10.1061/jyceaj.0004523
Abstract
The longitudinal dispersion coefficient, DL, is evaluated on the basis of a one-dimensional analysis as affected by large bed roughness in a laboratory flume. The experimental results have shown that the dimensionless dispersion coefficient, DL/Yu*, in which Y is the water depth and u* is the bed shear velocity, is a function of the relative roughness height, Y/h, and the relative roughness spacing, X/Y. It is also found that DL/Yu* reaches a maximum value at a roughness density h/X = 0.111. The commonly used equation for estimating the longitudinal dispersion coefficient (DL = C Yu*) is also examined. It is found that this straight line relation between DL and Yu* is no longer valid for values of Yu* greater than 0.1 sq ft per sec (0.009 m²/s).Keywords
This publication has 0 references indexed in Scilit: