Numerical simulation of elliptical particles sedimentation in power-law fluid using the improved smoothed profile-lattice Boltzmann method

Abstract

Simulation of non-circular particles movement in the power-law fluid has not been considered in detail because of the challenges existing in the identification of particles. Accordingly, the present work has numerically considered the elliptical particles sedimentation in a two-dimensional box filled with the power-law fluid by using the improved smoothed profile-lattice Boltzmann method (iSPM-LBM). The SPM was applied to assign the fluid–solid interaction. Furthermore, the effects of orientation, density ratio and aspect ratio on the flow patterns during the sedimentation of the single ellipse were considered. The results showed that decreasing the power-law index and increasing the aspect ratio and also, density ratio caused the stability of the particles to disappear, such that they started oscillation. The oscillation in the shear-thinning fluid was more than that observed in others. In the next case, the dynamics of two identical ellipses was investigated in different initial inclinations. It was observed that the sedimentation of particles in the shear-thinning fluid happened more quickly in comparison to the other two ones. Also, the kissing phenomenon did not occur for all cases considered. The results of the present study were then compared with those obtained from the previously published works on the Newtonian fluid, showing a good agreement.