Concentration and velocity profiles of sediment‐water mixtures using the drift flux model

Abstract

In this paper, the concentration and velocity profiles of sediment water mixtures for open-channel flows are modelled numerically and validated with experimental results. A continuum approach, the drift flux model, is used. The mixture consists of volume fractions with different particle sizes. Hindered settling is taken into account with the closure relation of Richardson and Zaki. Transport equations are used for sediment transport. Turbulence is modelled with the LES (large eddy simulation) WALE model. The discretization of the transport and Navier-Stokes equations is done with the finite volume method. The Navier-Stokes equations are solved using a fractional step method. The numerical results are compared with experimental results concerning open-channel flows.

Analysis and discussion of two fluid modelling of pipe flow of fully suspended slurry

“…Model [16], might be interpreted as a simplified formulation of the two-fluid approach, which is valid under the hypothesis that the particles are rapidly accelerated to their terminal velocity. This assumption is called "local equilibrium approximation" and, broadly speaking, is acceptable if the particles are sufficiently fine.…”

Computational Fluid Dynamics Modelling of Liquid–Solid Slurry Flows in Pipelines: State-of-the-Art and Future Perspectives

“…Finally, the Mixture Model has recently been coupled with more complex turbulence models such as the LES (Large Eddy Simulation) WALE model [168]. In this study, the numerical description of transport of unsteady sediment-water mixtures, with different particle diameters, in an open channel (tilting flume) is shown to be able to match experimental data with a high degree of accuracy for low and high particle concentrations, but with a less favorable agreement for intermediate particle concentrations.…”

Flood Suspended Sediment Transport: Combined Modelling from Dilute to Hyper-Concentrated Flow

“…with exponent α equals to unity. Limitations of this Rouse-type formulation have been evidenced by the measurements of Sumer et al [27], Greimann and Holly [9], Jha and Bombardelli [10], Kironoto and Yulistiyanto [28], and Goeree et al [16]. Owing to its derivation from diffusion theory, the Rouse formula provides a single-phase approach focusing on the sediment particles.…”

“…Within the field of sediment profiling a range of mathematical concepts has been adopted to predict the concentration profile. Goree et al [16] used continuum theory and incorporated the effect of drift flux due to flow turbulence implemented using large-eddy simulation. However, it was found that the computed results were less accurate in the near-wall region (also agree with [17,18]).…”