Regarding the hydrodynamic study, the main difficulty at high
flow rates is associated with low values of diffusion coefficients
(D e 10-9m2 s-1) inducing Peclet numbers that are too high for
the convection-diffusion calculations. Consequently, the local
mesh size should be small enough to decrease the mesh Peclet
number. In the case of a geometry featuring channel dimensions
of hundreds of micrometers, the resulting mesh would induce
computational limitations. One way to solve this problem for a
fixed length of channel (L ) 2000 ím) is to increase the diffusion
coefficient in order to maintain a moderated constant Peclet
number. The Peclet number introduced in eq 5 can be also defined
as