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Riser hydrodynamics: Simulation using kinetic theory
Author(s) -
Neri Augusto,
Gidaspow Dimitri
Publication year - 2000
Publication title -
aiche journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.958
H-Index - 167
eISSN - 1547-5905
pISSN - 0001-1541
DOI - 10.1002/aic.690460108
Subject(s) - fluidization , mechanics , computational fluid dynamics , particle (ecology) , viscosity , flow (mathematics) , two fluid model , kinetic energy , compressibility , physics , kinetic theory , thermodynamics , materials science , geology , classical mechanics , fluidized bed , oceanography
Computational fluid dynamics (CFD) for fluidization is reaching maturity (Roco, 1998). It has become common practice to compare time‐averaged solid velocities and concentrations to measurements of fluxes and densities. The dynamic behavior of the riser, however, has not been previously compared to experiments. This article shows that the dynamics of solids flow in the riser is in the form of clusters, but the time‐averaged particle concentrations and fluxes give us the core‐annular flow regime in agreement with measurements. The computed clusters, which are essentially compressible gravity waves, produce major frequencies of density oscillations in agreement with measurements. The model and the CFD code compute granular temperature distributions, agreeing qualitatively with data. For volume fraction around 3–4%, which is the average particle concentration in the riser, the computed viscosity agrees with our experimental measurements.