Numerical study of fluid–particle flows in power-law fluids using a fictitious boundary approach

Abstract The dynamics of solid particles and fluid solid interaction in particulate flows with a power law model are examined. An Eulerian approach is employed to simulate this flow across a fixed computational grid, utilizing the fictitious boundary method (FBM) to efficiently handle complex geometries. The multigrid finite element solver FEATFLOW is extended to account for non-Newtonian fluids. Three types of rheological behavior are considered: (i) shear-thinning ( n = 0.9 ) , (ii) Newtonian ( n = 1 ) , and (iii) shear-thickening ( n = 1.1 ) . Numerical experiments are conducted with two falling particles, focusing on the drafting, kissing, and tumbling phenomena in power-law fluids. Results from these experiments are presented and compared across shear-thinning, Newtonian, and shear-thickening fluids by varying the initial particle positions and the particle radii. The effects of particle–particle interactions on particle motion and the overall behavior of the fluid–particle system are analyzed. This study validates the FBM by comparing it with benchmark results and offers valuable insights into particle–fluid interactions.