variavel0=<b>Luben Cabezas-Gómez</b> - lubencg@sc.usp.br Núcleo de Engenharia Térmica e Fluidos, EESC-USP
<b>Luciano Vieira de Souza</b> - souzalv@sc.usp.br Núcleo de Engenharia Térmica e Fluidos, EESC-USP
<b>Fernando Eduardo Milioli</b> - milioli@sc.usp.br Núcleo de Engenharia Térmica e Fluidos, EESC-USP
<b>Abstract.</b> A  methodology  of  identification  and  characterization  of  coherent  structures  mostly  known  as clusters is applied to  hydrodynamic  results  of  numerical  simulation  generated for the riser of  a  circulating  fluidized  bed.  The  numerical  simulation  is  performed  using  the  MICEFLOW  code,  which  includes  the  two-fluids IIT`s hydrodynamic  model B.  The  methodology  for  cluster  characterization  that  is  used  is  based  in  the  determination  of  four  characteristics,  related  to  average  life  time,  average  volumetric  fraction  of  solid,  existing  time  fraction  and  frequency  of  occurrence.  The  identification of clusters is performed applying a criterion  related to the time average value of the volumetric solid fraction. A qualitative rather quantitative analysis is performed mainly owing to  the unavailability of operational data used in the considered experiments. Concerning qualitative analysis, the simulation results are in  good agreement with literature. Some quantitative comparisons between predictions and experiment were also presented to emphasize  the capability of the modeling procedure regarding the analysis of macroscopic scale coherent structures.
<b>Keywords.</b> coherent structures, clusters, numerical simulation, gas-solid flow, circulating fluidized bed.