A4
 
Peclet number for the wall-jet electrode
 

The mass transport equation is:

(A4.1)

where (under a 1st order convection approximation):

and (A4.2)

and

, 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:

(A4.5)

Similarly the velocity expressions become:

(A4.6)
(A4.7)

Substituting for vr and vz gives:

(A4.8)

where Ps is the (shear rate) Peclet number:

= (A4.9)

Hence:

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

However the dimensionless current:

(A4.11)

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.