Hydrodynamic modeling and analysis of two-phase non-Newtonian coal/water slurries

Abstract

The two-phase hydrodynamic theory of fluid/solids flow has been utilized to extend the non-Newtonian power-law model to describe the solids rheology for nonhomogeneous slurry flow. The model developed predicts the two-dimensional spatial and temporal variations of solids and liquid velocities and concentration for non-Newtonian power-law slurries experiencing high shear rates typically found in diesel engine injection systems. Comparisons with analytical solutions and literature data for single-phase Newtonian and non-Newtonian flows are presented. The model has been validated using Newtonian single-phase (pure water and No. 2 diesel fuel) and non-Newtonian two-phase (coal/water slurry) capillary tube viscometer shear rate, viscosity, mass flow rate and pressure drop data. Results applicable for typical diesel engine injection systems are presented. The results from this model can be used to calculate the erosion rates at the injection nozzle boundaries and the solids loading at its exit.