Evaluation of different mathematical models in the CFD-DEM simulation of conical spouted bed fluid dynamics

Abstract

The input parameters, empirical, and semi-empirical models significantly influence the responses obtained by CFD-DEM simulations. In this work, the effects of three turbulence models, three conditions of the particle rotation, and five drag models, on the fluid dynamic behavior of a conical spout bed applied to the drying of sorghum grains were evaluated. Experimental data on the solids pressure drop, height, and shape of the fountain were used to validate the simulations. Results showed the importance of including the particle rotation in the model to approximate the results simulated with the experimental behavior. Compared with experimental data, considering the particle rotation by the Dennis et al. model, the deviation was 2% for the fountain height and 9.18% for the pressure drop. Whereas, for the model without the particle rotation, the deviations were 106.33 and 42.31% for the fountain height and pressure drop, respectively. For the analyzed case, the standard k-ε turbulence model showed a greater agreement with the experimental data. For the drag models evaluated, the best fit with the experimental data was obtained by the Koch-Hill drag model, followed by the Gidaspow model, with deviations less than 10%.

Keywords

• drag model
• particle rotation
• turbulence model
• sorghum grains