Fh. Bark et al., JOULE HEATING IN ELECTROCHEMICAL-CELLS EXPERIENCING NATURAL-CONVECTION AND ELECTROLYTE STRATIFICATION, Russian journal of electrochemistry, 34(4), 1998, pp. 393-402
The Joule heating is studied theoretically in a simple electrochemical
cell formed by two vertical metallic electrodes and two electrochemic
ally inert horizontal boundaries. The cell contains an aqueous solutio
n of a metal salt as the electrolyte. The voltage across the cell is a
ssumed to be specified. A convective electrolyte flow emerges in the c
ell in the course of electrolysis. A steady-state mode of the cell ope
ration, which is characterized by large values of the Rayleigh number
and the applied voltage, is considered. The heat contribution in the n
atural convection is shown to be negligible, compared with the convect
ion that is due to changes in the solution density caused by variation
s of its composition. In the steady-state mode, the solution becomes s
tratified, which affects significantly the electrolyte flow. The elect
ric current distribution in the vertical direction is shown to be nonu
niform, which results in a nonuniform heat generation and a nonuniform
temperature distribution. The procedure developed can be useful (afte
r slight modifications) for studying heat effects in lead-acid batteri
es intended for electric engines.