Evaluating the performance of the Mixture Model coupled with High and Low Reynolds Turbulence closures in the numerical description of concentrated solid-liquid flows of settling particles

摘要

In this manuscript, Computational Fluid Dynamics (CFD) studies applying the Mixture Model coupled with both a High Reynolds and a Low Reynolds k-ε turbulence closures, were used to describe experimental pressure gradients and particle concentration profiles from the literature, for concentrated solid-liquid flows of settling particles in a horizontal pipe above the critical deposition velocity. With this work a new Mixture Model formulation is presented, incorporating the Jones-Launder Low Reynolds k-ε turbulence closure, to overcome the excessive turbulence production observed in the numerical studies using the High Reynolds k-ε turbulence model. Additionally, this formulation provides a more accurate representation of the wall turbulence damping phenomena, observed in the experimental testing for the flow of higher particle concentrations suspensions and higher flow velocities. Knowledge on the conditions that cause turbulence attenuation on solid-liquid flows is still scarce in the literature and of considerable value for industrial applications.