<abstract xmlns="http://www.w3.org/1999/xhtml"><p>Collisional interactions in a sheared granular body are typical for intense bed load transport and they significantly affect behavior of flow carrying bed load grains. Collisional mechanisms are poorly understood and modelling approaches seldom accurately describe reality. One of the used approaches is the kinetic theory of granular flows. It offers constitutive relations for local shear-induced collision-based granular quantities - normal stress, shear stress and fluctuation energy - and relates them with local grain concentration and velocity. Depth distributions of the local granular quantities produced by these constitutive relations have not been sufficiently verified by experiment for the condition of intense bed load transport in open channels and pressurized pipes. In this paper, results from a tilting-flume facility including measured velocity distribution and deduced concentration distribution (approximated as linear profiles) are used to calculate distributions of the collision-based quantities by the constitutive relations and hence to test the ability of the kinetic-theory constitutive relations to predict conditions observed in these collision-dominated flows. This test indicates that the constitutive relations can be successfully applied to model the local collisional transport of solids at positions where the local concentration is not lower than approximately 0.18 and not higher than approximately 0.47.</p></abstract>

Collisional interactions in a sheared granular body are typical for intense bed load transport and they significantly affect behavior of flow carrying bed load grains. Collisional mechanisms are poorly understood and modelling approaches seldom accurately describe reality. One of the used approaches is the kinetic theory of granular flows. It offers constitutive relations for local shear-induced collision-based granular quantities - normal stress, shear stress and fluctuation energy - and relates them with local grain concentration and velocity. Depth distributions of the local granular quantities produced by these constitutive relations have not been sufficiently verified by experiment for the condition of intense bed load transport in open channels and pressurized pipes. In this paper, results from a tilting-flume facility including measured velocity distribution and deduced concentration distribution (approximated as linear profiles) are used to calculate distributions of the collision-based quantities by the constitutive relations and hence to test the ability of the kinetic-theory constitutive relations to predict conditions observed in these collision-dominated flows. This test indicates that the constitutive relations can be successfully applied to model the local collisional transport of solids at positions where the local concentration is not lower than approximately 0.18 and not higher than approximately 0.47.

Laboratory testing of granular kinetic theory for intense bed load transport

Journal of Hydrology and Hydromechanics

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 License.

{"article-title":"Laboratory testing of granular kinetic theory for intense bed load transport"}

Collisional interactions in a sheared granular body are typical for intense bed load transport and they significantly affect behavior of flow carrying bed load...

Laboratory testing of granular kinetic theory for intense bed load transport

Pubblicato online: 14 ago 2018

Pagine: 330 - 336

Ricevuto: 28 dic 2017

Accettato: 20 feb 2018

DOI: https://doi.org/10.2478/johh-2018-0012

Parole chiave
Granular flow, Sheet flow, Sediment transport, Grain collision, Tilting flume experiment

© 2018 Václav Matoušek, published by Sciendo

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 License.

Laboratory testing of granular kinetic theory for intense bed load transport

Pubblicato online: 14 ago 2018

Pagine: 330 - 336

Ricevuto: 28 dic 2017

Accettato: 20 feb 2018

DOI: https://doi.org/10.2478/johh-2018-0012

Parole chiaveGranular flow, Sheet flow, Sediment transport, Grain collision, Tilting flume experiment

© 2018 Václav Matoušek, published by Sciendo

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 License.

Parole chiave
Granular flow, Sheet flow, Sediment transport, Grain collision, Tilting flume experiment