J. Krysa et Aa. Wragg, FREE CONVECTIVE MASS-TRANSFER AT DOWN-POINTING PYRAMIDAL ELECTRODES, International journal of heat and mass transfer, 39(6), 1996, pp. 1297-1305
A limiting current technique was used for the measurement of the free
convective mass transfer rate at entire down-pointing pyramids and als
o at the individual faces of the pyramids. The cathodic deposition of
Cu2+ ions at electrodes of varying geometries was used as the mass tra
nsfer process, the supporting electrolyte being sulphuric acid. The ma
ss transfer rate at a single inclined pyramidal surface was correlated
by the equation Sh(L) = 0.78(Ra-L,Ra-theta)(0.25) for the Ra-L,Ra-the
ta range 9.3 x 10(6) to 2 x 10(11). The mass transfer data for the ent
ire pyramid were correlated using a method which includes an interfere
nce factor taking account of the fact that the upward-facing horizonta
l surface is exposed to fluid which has already been depleted in coppe
r ions. The dependence of the interference factor on the aspect ratio
of the pyramid (L/b) was established.