hi everbody

i am having bit of confusion about the choosing correct approach for multhiphase with high dispersed phase holdup for example in case of gas fluidized bed with high solid up, whether we have choose Eulerian-discrete element method(DEM) or Eulerian-Eulerian two fluid method. in dense bed, particle -particle interaction will be dominant when compared to other force, should we use DEM based approach for dense bed? otherwise any criteria for high solid holdup for choosing DEM or two fluid approach

one more question about high solid up is there any range for solid holdup for dense and medium bed.. or under what basis classified the dense bed

with regards CFDUSERIN

Some criteria for choosing your approach:

-Is the total number of particles in the bed sufficiently low to make DEM feasible? -Eulerian-Eulerian models based on the kinetic theory of gases do not (AFAIK) account for particle shape/asymmetry. This may/may not be important in your case. -Eulerian-Eulerian models based on the kinetic theory of gases are routinely used to model fluidised beds. -DEM has the distinct advantage of being able to deal with heterogeneous mixtures of arbitrarily different particles (shape, size, density, ...). Eulerian-Eulerian models cannot deal with that effectively. -DEM models account for the finite dimensions of particles. This may be important in some cases e.g. particles interacting with baffles/gratings.