Numerical simulation of the effects of non-Newtonian property of the solvent on particle suspension rheology

Abstract

To investigate the effects of the non-Newtonian properties of solvents on particle suspension rheology (non-Newtonian property and viscosity), we analyzed suspension flows with different solvent characteristics. We used the power-law model to express the non-Newtonian properties of solvents. The power-law index of the suspension was denoted as n sus. and that of the solvent as n sol . to distinguish between their non-Newtonian properties. Besides, to evaluate the non-Newtonian property of the particle suspension, we estimated its power-law index n sus . by comparing its particle velocity with the velocity profile of a power-law fluid. As a result, regardless of the different area fraction, the power-law index of the particle suspension was lower than that of the solvent for n sol . = 0 . 6 , 0.8, and 1.0. On the other hand, for n sol . = 0 . 4 and ϕ ≥ 1 . 57 , the power-law index of the particle suspension was higher than that of the solvent. Regarding the particle position, particles for n sol . = 0 . 4 were more concentrated on the wall side than those of the suspensions with n sol . = 0 . 6 , 0.8, and 1.0. Thus, this study confirms that a change in the non-Newtonian property of a suspension due to interactions between particles and power-law fluids is an essential factor when discussing the rheology of suspensions.