A numerical simulation analysis of the effect of the interface drag function on cluster evolution in a CFB riser gas-solid flow
AUTOR(ES)
Gómez, L. C., Milioli, F. E.
FONTE
Brazilian Journal of Chemical Engineering
DATA DE PUBLICAÇÃO
2004-12
RESUMO
The dynamics of formation, dissipation and breaking of coherent structures in the riser gas-solid flow of a circulating fluidized bed (CFB) are evaluated by numerical simulation. The simulation is performed using the MICEFLOW code, which includes IIT's two-fluid hydrodynamic model B. The methodology for cluster characterization is used from Sharma et al. and is based on determination of four characteristics, average lifetime, average volumetric fraction of solid, existence time fraction and frequency of occurrence. Clusters are identified applying a criterion for the time average value of the volumetric solid fraction. A qualitative analysis of the influence of different drag function correlations on the hydrodynamics of the flow, including the evolution of coherent structures, is performed. The simulation predictions are also compared to experimental results. The results indicate that the choice of a correlation for drag function should be quite judicious. Finally it is shown that the mean clustering criteria of Sharma et al. should be modified to take into account other factors that influence cluster dynamics.
Documentos Relacionados
- Gas-solid two-phase flow in the riser of circulating fluidized beds: mathematical modelling and numerical simulation
- On the statistical steady state gas-solid flow in a riser as predicted through a two-fluid simulation
- Some modeling and numerical aspects of the two-fluid simulation of the gas-solids flow in a CFB riser
- On the application of self-organizing neural networks in gas-liquid and gas-solid flow regime identification
- Calibration of simulation parameters for wind erosion gas-solid two-phase flow in arid and semiarid soils