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

Autor(es)

Cabezas-Gómez, L. ^[1] ; Milioli, Fernando Eduardo

Afiliação do(s) autor(es)

^[1] Universidade de São Paulo (USP). Escola de Engenharia de São Carlos. Departamento de Engenharia Mecânica - Brasil

• Tipo de documento: Artigo Científico
• Fonte: Brazilian Journal of Chemical Engineering; v. 21, n. 04, p. 569-583, Oct. 2004.
• Área do conhecimento: Engenharias - Engenharia Mecânica
• Assunto(s): Fenômenos de transporte Escoamento Modelos matemáticos Simulação de sistemas

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. (AU)

• Processo FAPESP: 02/12038-8 - Modelagem e simulacao euleriana de escoamentos gas-solido usando a teoria cinetica dos escoamentos granulares.
• Beneficiário: Luben Cabezas Gómez
• Modalidade de apoio: Bolsas no Brasil - Pós-Doutorado
• Processo FAPESP: 98/13812-1 - Modelagem matemática e simulação numérica de escoamentos bifásicos gás-sólidos em colunas de leito fluidizado circulante
• Beneficiário: Luben Cabezas Gómez
• Modalidade de apoio: Bolsas no Brasil - Doutorado