Computational fluid dynamics: applications in pharmaceutical technology - Computer-Aided Applications in Pharmaceutical Technology - page 242

Schematic representation of different grid structures:
(a) full grid case; (b) grid case 1; and (c) grid case 2
(reprinted from Coates et al., 2004; with permission
from John Wiley & Sons)

Figure 7.5

infl uenced the fl ow fi eld in the mouthpiece. With the increase of grid
voidage, the straightening effect of the grid on airfl ow decreased
(Figure 7.6), leading to an increased amount of powder retained within
the device. The mouthpiece length was found to have less signifi cant
infl uence on inhaler performance, with slightly reduced device retention
in a shorter mouthpiece.
In one of the studies that followed, Coates et al. (2007) investigated the
infl uence of mouthpiece geometry on the extent of throat deposition and
on the amount of drug retained in the inhaler. CFD analysis was performed

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CFD simulated particle tracks of dispersed powder:
(a) full grid case; (b) grid case 1; and
(c) grid case 2 (reprinted from Coates et al., 2004;
with permission from John Wiley & Son)

Figure 7.6