Modelagem matemática e computacional de escoamentos gás-sólido em malha adaptativa dinâmica

Abstract

Gas-solid flows are found in many industrial applications, such as pneumatic conveying systems, pollution control processes and fluidized beds. The modeling of the most relevant phenomena in these flows is fundamental to understand the behavior of each one of the phases, how one phase affects the movement of the other, and thus, how their flow influence on industrial processes in general. Therefore, the objectives of this dissertation are to implement, in the MFSim computational code, the forces acting on the transport of solid particles, the necessary boundary conditions, the coupling between the phases of the flow, an interparticle collision model as well as between particles and immersed boundary, based on an Euler-Lagrange approach. Verifying and validating these implementations are a crucial step of this work. To verify and validate them, four different cases were simulated. The first one evaluates the momentum of the two phases of the flow in order to compare with the results of an analytical solution validating the coupling between fluid and particles. The second one is related to the validation of interparticle collision comparing the simulated results with the ones from the kinetic theory of gases. In the third one, the collision of particles with an immersed geometry is verified evaluating the optimization accomplished in the present work. In this case of a jet impacting on a surface, some parameters are varied to evaluate its behavior. The last case is focused on the validation of particle dispersion due to turbulence, through a comparison of experimental data provided in the literature with results obtained from simulations of a grid turbulence. The results obtained for all cases are adequate, and so, it is concluded that, using the MFSim code, it is possible to simulate gas-solid turbulent flows, in which the interactions between fluid and particles, between two particles, and between particles and immersed boundary are relevant.