Modeling the Turbulent Flow of Pulp Suspensions

Abstract

Pulp fiber suspensions are complex systems because the components present singular and complex interactions between them. A mechanistic model for the turbulent flow regime of industrial pulp suspensions was developed on the basis of a CFD code, using the chemical engineering module of COMSOL Multiphysics software. The standard k-ε turbulence model, chosen to simulate turbulence, was tested and validated using four different industrial pulp suspensions previously characterized experimentally. The modeled pressure drop profiles agree very well with the experimental results obtained in a pilot rig. Therefore, the k-ε turbulence model for the simulation of pulp fiber suspension flows, associated with experimental rheological data, proved to be a prompt strategy to attain good prediction of pressure drop for fiber suspension flows. Moreover, the adjustment of the turbulence parameters confirmed previous studies, where it was concluded that the existence of particles, such as fibers, in a fluid flow induces a turbulence damping.