| A number of industrial applications involve the cleaning of a stream of air contaminated with particles. In some instances, the proper design and operation of the device employed are crucial to the performance of the overall industrial process. Therefore, such an important feature should be looked at from a fundamental standpoint.; The design and operation of air-solid separators require characterization and optimization of complex phenomena. Nowadays, empiricism is not adequate to elucidate many of the aspects of interest in the separation process; rather, mathematical modeling based purely on physics has become more attractive with the development of powerful computers and reliable computational fluid dynamics (CFD) software.; The main goal of this research is the design of a swirler separator with the aid of computational fluid dynamics. A swirler separator is basically a tube fitted with static blades at the entry. As incoming particle-laden air passes through the blades, it swirls, hence effecting separation of dust particles from air. An efficient design should offer as low a pressure drop across the unit as possible, while maintaining reasonable cleaning efficiency. For such a design task, the fluid flow is predicted by solving the averaged continuity and Navier-Stokes equations. Since the flow is turbulent, the Boussinesq hypothesis is used to describe the stress distribution in the flow field and the standard {dollar}kappa{dollar}-{dollar}varepsilon{dollar} model to calculate the turbulent viscosity. The solid-phase is modeled by following a Lagrangian methodology in which a Newtonian force balance is used to track the particles throughout the flow field. A stochastic method is employed to account for the dispersion of particles due to turbulence of the fluid-phase.; Successful development of the CFD model for both phases translates into a powerful simulation tool. The assessment of success can be made through comparisons between model predictions and experimental data, including pressure and velocity field to validate the fluid-phase model as well as dust collection to verify the particulate-phase model.; Finally, after approval of the model, it is used along with complementary experiments to determine a final configuration for the swirler separator capable of fulfilling the constraints stated in the description of the problem. |
