Modelling of intense collisional sediment transport with turbulent suspension

Investigatordoc. Ing. Zdeněk Chára, CSc.
Co-Investigatordoc. Ing. Zdeněk Chára, CSc.
Duration2019 - 2022

Solid-liquid flows in geomorphological and industrial processes transport grains which are often
supported by a combination of mutual collisions and turbulent suspension. A dominating
support mechanism depends primarily on grain size and on local position in a layered structure
of the solid-liquid flow. The proposed project deals with flows in which some grains are
suspended by turbulent eddies of carrying liquid and the rest is transported as collisional bed
load. We focus on steady-state uniform open-channel flow with monodisperse or bimodal
sediment. Results of our previous research on purely collisional flows will be exploited to
theoretically and experimentally describe the flow internal structure and its impact on the
sediment discharge and open-channel friction/capacity. Granular rheology based approaches,
including the kinetic theory, will be employed to formulate a mathematical model and its
numerical solver. Model predictions of the flow internal structure and flow integral quantities will
be calibrated and validated by experiments in a laboratory tilting flume.

The goal of the project

Theoretical and experimental description of internal structure of open-channel flow with
combined bed+suspended load above mobile bed. Effect of flow structure on sediment
discharge, channel resistance and capacity based on granular flow rheology. Mathematical
model and its numerical solution.