A numerical simulation analysis of the effect of the interface drag function on cluster evolution in a CFB riser gas-solid flow



Document title: A numerical simulation analysis of the effect of the interface drag function on cluster evolution in a CFB riser gas-solid flow
Journal: Brazilian journal of chemical engineering
Database: PERIÓDICA
System number: 000308914
ISSN: 0104-6632
Authors: 1
Institutions: 1Universidade de Sao Paulo, Escola de Engenharia de Sao Carlos, Sao Carlos, Sao Paulo. Brasil
Year:
Season: Dic
Volumen: 21
Number: 4
Pages: 569-583
Country: Brasil
Language: Inglés
Document type: Artículo
Approach: Experimental, aplicado
English abstract 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
Disciplines: Química
Keyword: Ingeniería química,
Estructuras coherentes,
Cúmulos,
Función de arrastre,
Flujo gas-sólido,
Lecho fluidizado circulante
Keyword: Chemistry,
Chemical engineering,
Coherent structures,
Clusters,
Drag function,
Gas-solid flow,
Circulating fluidized bed
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