CONICET | Buscador de Institutos y Recursos Humanos

Multiphase solid-gas ﬂows may be found in many industrial applications,from oil reﬁning processes to hydrogen production reactors.In particular,we focus our interest in the dynamics of solid particles in a circulating ﬂuidized bed riser of a Fluid Catalytic Cracking(FCC)unit,in which the solid particles distribution is one of the main variables in the global efﬁciency of the unit.In the last decades, much effort has been put in the development of Euler-Euler models with granular energy coupling to simulate this kind of problems due to the good balance between computational cost and accuracy of the numerical solution. In this work, in order to have a closure with the Navier-Stokes equations for the solid phase, we set the kinetic theory of granular ﬂow with solid pressure and stress tensor models, while Wen Yu and Ergun correlations are used to calculate the drag coefﬁcients. All the numerical simulations Rare carried out with the fully unstructured open source code OpenFOAM, based on the ﬁnite volume method. In addition, an iterative procedure based on a combination of PISO and SIMPLE method (called PIMPLE) is adopted and a proper discussion of its beneﬁts is performed. To validate the solver, we present two widely studied multiphase ﬂow problems.The ﬁrst one consists on a sedimentation column starting from a uniform solid volume fraction suspension. The second one is based on a falling block of solid particles in a pure gas environment. Finally, we study a problem of a ﬂuidized bed of particles with a constant gas injection from below. For this case, we are able to verify the good performance of the solver. In order to do this, we analyze the time and space average proﬁles of the solid volume fraction in comparison with the numerical and experimental results from several authors.