Particle-scale modelling of gas–solid flow in fluidisation
✍ Scribed by A B Yu; B H Xu
- Publisher
- Wiley (John Wiley & Sons)
- Year
- 2003
- Tongue
- English
- Weight
- 908 KB
- Volume
- 78
- Category
- Article
- ISSN
- 0268-2575
- DOI
- 10.1002/jctb.788
No coin nor oath required. For personal study only.
✦ Synopsis
Abstract
Various approaches have been proposed to model the gas–solid two‐phase flow at different time and length scales, including the so‐called two‐fluid model (TFM), direct numerical simulation (DNS) and combined continuum and discrete model (CCDM). This paper briefly discusses the key features of these models and their relative merit with special reference to modelling gas fluidisation. Focus is then given to CCDM in which the motion of individual particles is obtained by solving Newton's second law of motion and fluid flow by the Navier–Stokes equation based on the concept of local average. The applicability of CCDM is highlighted by its successful simulation of complicated phenomena associated with the transition between fluid‐like and solid‐like behaviour in raceway formation and bed expansion. At the same time, the usefulness of the resulting particle‐scale information is demonstrated in elucidating the fundamentals governing the gas–solid flow. Finally, areas for future development are discussed.
© 2003 Society of Chemical Industry
📜 SIMILAR VOLUMES
NOTATION diffusion coefficient of Fe(CN&" in the solution; m2/sec diameter of the sphere; m mass-transfer coefficient; m/set translational velocity; m/set angular velocity: rad./sec kinematic viscosity of the fluid; m\*/sec Reynolds number for translation, Vd/v Reynolds number for rotation, od\*/v R
WE HAVE the following comments to make in reply to the communication by Mr. Godard and Professor Richardson: I. Equation (I) in our paper [ I] refers to a bubbling fluidised bed with constant voidage fraction between bubbles. Most liquid-solid systems are non-bubbling and of course fall outside the
Axial solid velocity, solid volume fraction, and solid shear viscosity were computed in the riser of a circulating puidized-bed reactor using a two-phase 2-0 computational fluid dynamic model. The time-averaged model predictions agree well with the experimental data of Miller and Gidaspow (1992). Th