A general two-phase turbulent flow model applied to the study of sediment transport in open channels

Abstract

a b s t r a c tA numerical model for the general description of the sediment-laden flow is developed based on an Euler-Euler approach of the two-phase turbulent flow theory. The basic equations of the model are the Reynolds averaged equations of motion for both the fluid and the sediment phase in addition to the Reynolds averaged continuity equations for the mixture and for the sediment phase. The fluid phase and the sediment phase are coupled through their interaction forces including resistance force, inertia force, and lift force. Turbulence closure of the fluid phase is based on the conventional k-e model while an algebraic particle turbulence model is applied to the sediment phase. The numerical method is based on the modified SIMPLE scheme. The model is applied to the computation of saturated sediment-laden flows and also the non-equilibrium transport of sediment by unidirectional flows under simple erosion and simple deposition conditions. The numerical results are well verified by the available experimental data. The vertical velocity of the sediment phase is also shown to be in very good agreement with the fall velocity of the sediment particles, which strongly support the assumption of Rouse's diffusion theory for suspended sediment under steady state.

Numerical prediction of fully-suspended slurry flow in horizontal pipes

“…The turbulent Schmidt number for volume fractions may in some sense be interpreted as the ratio of turbulent momentum transport to the turbulent transport of phase mass. However, the numerical value of σ α is not well established in the literature because no single constant value can be used to match the various sets of experimental data [41,42]. These values typically fall in the range 0.2 to 0.9.…”

Extension ofk-ωturbulence closure to two-phase sediment transport modelling: Application to oscillatory sheet flows

“…In particular, two-phase modelling approaches have been implemented to study sediment scour (e.g., [9][10][11]), non-uniform open channel flow sediment transport (e.g., [12]), and even estuarine sediment transport (e.g., [13]). …”

Numerical Prediction of Particle Distribution of Solid-Liquid Slurries in Straight Pipes and Bends

“… is the turbulent kinematic viscosity of the carrier fluid phase, determined by turbulence modeling; and   is the turbulent Schmidt number for volume fractions. The turbulent Schmidt number for volume fractions is not well established, in the sense that no single constant value of σα can be used in the numerical simulations to match the various sets of experimental data (Shirolkar et al, 1996), but rather previous workers (Chen, 1994;Chen et al, 2011) have found that different constant values are needed for different cases. These values typically fall in the range of 0.2 to 0.9.…”