1 research outputs found
Gas Flow Visualization in Low Aspect Ratio Packed Beds by Three-Dimensional Modeling and Near-Infrared Tomography
Nonuniform
local flow inside randomly porous media of gas–solid
packed beds of low aspect ratios ranging from 1.5 to 5 was investigated
by three-dimensional modeling and near-infrared tomography. These
beds are known to demonstrate heterogeneous mixing and uneven distributions
of mass and heat. The effects of the confining wall on flow dynamics
were found nonlinear, particularly for aspect ratios lower than 3.
High velocities were mainly observed in regions near the wall of aspect
ratio value of 1.5 and those of values higher than 3, owing to high
local porosities in these zones. Mass dispersion characterized both
by experimental near-infrared imaging and by particle tracking showed
discrepancies with literature models, particularly for aspect ratios
lower than 3. Uncertainties were more significant with the radial
dispersion due to bed size limits. Beyond this value, the wall affected
more the axial dispersion, confirming the nonlinear impact of the
wall on global hydrodynamics