Effect of specularity coefficient on hydrodynamic behaviors of slurry flows in horizontal pipes

Abstract

The Eulerian–Eulerian two-fluid model (TFM) in combination with the kinetic theory of granular flow (KTGF) and the Johnson and Jackson boundary condition is widely used to simulate multiphase flows in engineering. However, this model requires the calibration of several parameters. One of these parameters is the specularity coefficient, which characterizes the particle–wall collisions. Thus far, research on this parameter has been lacking in the field of slurry flow simulations. In this study, the integration of TFM with KTGF and the Johnson and Jackson boundary condition is used to simulate the transportation of sand–water slurry in horizontal pipes. The effects of different specularity coefficient values on the predicted solids wall shear stress, velocity, and concentration are analyzed. It is found that the solids wall shear stress increases with the specularity coefficient and is more sensitive to the smaller specularity coefficient. As the specularity coefficient increases, the profiles of the solids velocity and concentration are rotated clockwise, shifting the maximum velocity point to a higher vertical location and producing a plumper solids concentration profile. These qualitative conclusions may be used as a reference for the specularity coefficient tuning process in the field of slurry transport simulations.