Steady state laminar natural convection flow in an enclosed square cavity with two vertical electrodes due to electrolysis process with supporting electrolyte at limiting current condition is studied numerically. Concentration and electric potential distribution, and limiting current are determined.
Calculations are performed varying the concentration of supporting electrolyte with the other parameters fixed. The concentration distribution of reactant is almost independent of the variation of the concentration of supporting electrolyte. The presence of supporting electrolyte lowers the electric field and the values of the calculated limiting current. In addition, the concentration distribution of supporting electrolyte affects the density distribution, hence, the velocity profile in natural convection. The maximum velocity near electrode is lowered by the factor of the densification coefficient ratio approximately. In the case of excess of supporting electrolyte, potential gradient does not affect the concentration distribution of reactant but affects largely that of supporting electrolyte.