Effect of dispersed phase rheology on the drag of single and of ensembles of fluid spheres at moderate Reynolds numbers

Abstract

In this work, the effect of dispersed phase rheology on the drag phenomena of single and of ensembles of fluid spheres translating in an immiscible power-law continuous phase has been studied numerically at moderate Reynolds numbers. The results presented herein encompass the following ranges of conditions: 1 ≤ Re_o ≤ 200, 0.1 ≤κ≤ 50, 0.2 ≤ Φ ≤ 0.6, 0.6 ≤ n_i ≤ 1.6 and 0.6 ≤ n_o ≤ 1.6, thereby enabling the effects of the Reynolds number (Re_o), of the internal to external fluid characteristic viscosity ratio (κ), of the volume fraction of the dispersed phase (Φ) and of the two power-law indices (n_i, n_o) on drag coefficient to be delineated. This information facilitates the estimation of the rate of sedimentation of single fluid spheres and their ensembles in quiescent continuous phase. Within the range of conditions studied herein, the effect of the dispersed phase rheology is found to be rather small.