Peclet number for the wall-jet electrode

The mass transport equation is:


where (under a 1st order convection approximation):

and (A4.2)


, and (A4.3)

Defining the dimensionless lengths:

R = r/re and Z = z/re(A4.4)

and substituting for R and Z, gives the dimensionless form of the mass transport equation:


Similarly the velocity expressions become:


Substituting for vr and vz gives:


where Ps is the (shear rate) Peclet number:

= (A4.9)


a = a(R,Z,Ps)(A4.10)

However the dimensionless current:


is calculated from the flux at the electrode surface, where Z = 0. Furthermore R is integrated out, thus the dimensionless current is a sole function of the Peclet number. Note that this result is only valid for a 1st order convection approximation.