“…In this case, the solid phases are represented by particles and the motion of the particles is modeled by the solution of Newton's law applied in each particle. MFIX code is used in this work for the numerical simulations and this code supports both approaches: Two-fluid method (TFM) ( [39,40]) and fluid-DEM approach ( [27,52,53]). Next, we describe the governing equations for the latter approach (Eulerian-Lagragian or fluid-DEM) used in the present work.…”