Predicting mixing in fluidized-bed reactors with LES
PhD student: Mikael Stallgård
mas@fluent.se
Supervisors: Lars Davidson
lada@chalmers.se
Filip Johnson
fijo@entek.chalmers.se
Cooperation: Fluent Sweden
Sponsors: Fluent Inc and Chalmers
Publications: -
Start of project: January 2004


THE PROJECT
This is a cooperation project between the Department of Energy Conversion, and Department of Applied Mechanics (both at Chalmers) and Fluent Sweden.

The proposed project concerns mixing in fluidized-bed reactors applied to combustion of solid fuels, with special emphasize on large scale mixing of gas and solids in the freeboard (the part above the bed). Understanding of the mixing is crucial when establishing models applicable to commercial scale fluidized bed combustors (and gasifiers). The aim is to develop a CFD simulation tool and to verify the results with experiments carried out at the Department of Energy Conversion. The applicability of large eddy simulations (LES) will be investigated. Subgrid-scale models (SGS models) available in Fluent will be evaluated and it is expected that further development of SGS models will be needed. These will be implemented in Fluent as UDFs

As an alternative to LES, unsteady RANS (URANS) and hybrid LES/RANS will also be considered. The advantage of these methods is that they are more suitable for high-Reynolds number flow than LES. It is expected that further development of available turbulence models will be needed in order to make them suitable for two-phase flow.

Initially, the project is divided into the following steps:
  • Literature survey of previous related work both with respect to fluidized bed modeling and as a basis for theoretical description of large-scale flow structures;
  • Evaluation of present simulations of the freeboard and identification of critical parameters;
  • Establishment of an LES test case with simplified boundary conditions.

 

 
REFERENCES


This page, Predicting mixing in fluidized-bed reactors with LES, should be part of a frames system at www.tfd.chalmers.se/~lada/projects/proind.html
 
byilj
Webmaster:
Ingalena Ljungström
ilj@flowsim.se