Dispersive Force Basis for Concentration Profiles

Autor: Wilson, K. C., Pugh, F. J., Wilson, K. C., Pugh, F. J.
Zdroj: Journal of Hydraulic Engineering; July 1988, Vol. 114 Issue: 7 p806-810, 5p
Abstrakt: Sediment concentration measurements of particulate slurry flow provide new insights into intense movement of both bed load and suspended load at high concentrations. The submerged weight of the bed-load (contact-load) solids is transferred downward by means of the normal intergranular stress. Associated with this normal stress there is a granular component of the shear stress resisting motion. Only the remaining, fluid-based, component of the shear stress produces the fluid shear velocity which is involved in velocity distribution and other features of turbulent flow. Turbulent support of suspended load entails a dispersive force which can be evaluated on the basis of the usual flux analysis. This force involves a transfer of weight from the particles to the surrounding fluid, which has been measured experimentally. Combined with the inter-granular stresses mentioned above, this dispersive force gives a new method of linking bed-load and suspended-load components to calculate total-load concentration profiles.
Databáze: Supplemental Index