Effect of drag models on hydrodynamic behaviors of slurry flows in horizontal pipes

Abstract

The Eulerian–Eulerian method is efficient when dealing with liquid–solid slurry flows containing a large number of particles, but its reliability relies on an accurate description of liquid–particle interaction for which numerous interphase drag models have been proposed. However, the performance of these models has not been systematically evaluated when applied to slurry flows. In this study, slurries in horizontal pipes under various flow conditions are simulated using the Eulerian–Eulerian method. Six commonly used drag models, such as the Schiller–Naumann, Wen–Yu, Gibilaro, Gidaspow, Syamlal–O'Brien, and Huilin–Gidaspow models, are assessed based on their predictions of streamwise velocity, secondary flow, solid concentration, and liquid turbulent kinetic energy. Under normal operations, all models provide similar streamwise velocities and secondary flow patterns. However, the Schiller–Naumann model presents an intensified secondary flow and a flattened solid concentration profile. All models perform poorly for the solid concentration distribution, which may be corrected by considering the overall mean solid concentration. Additionally, the Wen–Yu model, which has previously been thought applicable only for dilute systems, behaves very closely to the Gidaspow model, which is usually recommended for dense fluidized beds.