Biomedical Engineering Reference
In-Depth Information
Figure 6.16
Concentration profiles obtained with (6.58) for a velocity of 1 mm/s in a channel of
radius
R
= 100
m
m.
or
U
F
(6.59)
Pe
=
>> 14
D
Relation (6.59) requires that the Péclet number should be larger than 14.
Second, the concentration
c
must be a slowly changing function of
x
(we have
even supposed in a first approximation that
¶
c
¶
c
); from (6.54), we derive
=
=
cste
¶
x
¶
x
Figure 6.17
Comparison of advection/diffusion between a parabolic profile (pressure-induced
flow) and a flat profile (electro-osmotic flow). In the moving coordinate system, diffusion is more
important for the parabolic profile than for the flat profile.
