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Geometry effects in Eulerian/Granular simulation of a turbulent FCC riser with a (kg-g)-KTGF model

Nazif, H. R ; Sharif University of Technology

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  1. Type of Document: Article
  2. DOI: https://doi.org/10.2202/1542-6580.2098
  3. Abstract:
  4. Three-dimensional, transient turbulent particulate flow in an FCC riser is modeled using an Eulerian/Granular approach. The turbulence in the gas phase is described by a modified realizable (kg-g) closure model and the kinetic theory of granular flow (KTGF) is employed for the particulate phase. Separate simulations are conducted for a rectangular and a cylindrical riser with similar dimensions. The model predictions are validated against experimental data of Sommerfeld et al (2002) and also compared with the previously reported LES-KTGF simulations of Hansen et al (2003) for the rectangular riser. The (kg-g)-KTGF model does not perform as well as the LES-KTGF model for the riser with a rectangular cross section. This is because, unlike the more elaborate LES-KTGF model, the simpler (kg-g)-KTGF model cannot capture the large scale secondary circulations induced by anisotropic turbulence at the corners of the rectangular riser. In the cylindrical geometry, however, the (kg-g)-KTGF model gives good prediction of the data and is a viable alternative to the more complex LES-KTGF model. This is not surprising as the circulations in the riser with a circular cross section are due to the curvature of the walls and not due to the presence of sharp corners
  5. Keywords:
  6. FCC ; Granular flow ; Riser ; Two-fluid model ; Anisotropic turbulence ; Circular cross-sections ; Cylindrical geometry ; Experimental data ; FCC riser ; Gasphase ; Geometry effects ; Granular flows ; Kinetic theory of granular flow ; Model prediction ; Particulate flows ; Rectangular cross-sections ; Secondary circulation ; Sharp corners ; Two fluid model ; Atmospheric boundary layer ; Computational geometry ; Confined flow ; Granular materials ; Plasma flow ; Plasmas ; Three dimensional ; Turbulence ; Fluid catalytic cracking
  7. Source: International Journal of Chemical Reactor Engineering ; Volume 8 , 2010 ; 15426580 (ISSN)
  8. URL: https://www.degruyter.com/view/j/ijcre.2010.8.1/ijcre.2010.8.1.2098/ijcre.2010.8.1.2098.xml