Computer Simulations of Low Concentrations Slurry Flows in Pipelines

In the paper a discrete system of particles carried by fluid is considered in a planar motion. The volumetric density of particles is taken between 1% and 2% so that they can be treated within the framework of a discrete dynamics model. The fluid is then considered as a carrier of particles. The Landau-Lifshitz concept of turbulence is used to describe the fluctuating part of fluid velocity. This approach is applied to simulate different regimes (laminar and turbulent) and various states of particle motion (moving bed, heterogeneous flow, and homogeneous flow) using only two parameters, which have to be determined experimentally. These two parameters, found for a particular pipe and for a particular velocity from a simple experiment, then have been used for simulations of flow for other pipe diameters and different velocities. The results agree favorably with experimental observations of the type of slurry flow and critical velocities identifying transitions from one type to another.