Study of the ability of multiphase continuum models to predict core-annulus flow
We use the well established core-annulus flow regime as a numerical benchmark to evaluate the sensitivity of gas-solids continuum models and boundary conditions to model formalisms and parameters. By using transient, 1D, grid-independent numerical solutions, we avoid the use of speculative closure terms and show that the kinetic theory of granular flow (KTGF) is sufficient to model core-annulus regime. That regime arises in the time-average solution as a consequence of the fluctuating motion of regions with high solids concentration. These fluctuations are most sensitive to the gravitational acceleration (g) and granular energy dissipation terms. The fluctuation frequency is ___. The effect of fluctuations is so dominant that decreasing the restitution coefficient (KTGF parameter) actually increases the average granular temperature. The wall boundary conditions for solids momentum and granular energy equations dictate the core-annulus flow regime. They must cause a net dissipation of granular energy at the wall for predicting that regime.
- Research Organization:
- National Energy Technology Laboratory (NETL), Pittsburgh, PA, Morgantown, WV, and Albany, OR (United States)
- Sponsoring Organization:
- USDOE - Office of Fossil Energy (FE)
- OSTI ID:
- 923665
- Report Number(s):
- DOE/NETL-IR-2008-001
- Journal Information:
- AIChE Journal (Online), Journal Name: AIChE Journal (Online) Journal Issue: 10 Vol. 53; ISSN 1547-5905
- Publisher:
- John Wiley & Sons, Inc., NY, for the American Institute of Chemical Engineers
- Country of Publication:
- United States
- Language:
- English
| Kinetic Theory of Granular Gases | book | July 2004 |
| MFIX documentation theory guide | report | December 1993 |
Boundary Conditions for Rapid Granular Flow: Flat, Frictional Walls
|
journal | March 1992 |
Radial variation in solid density in high velocity fluidization
|
book | January 1986 |
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