A mathematical model has been developed to predict the electrolyte velocity field, bubble distribution, current distribution, and mass‐transfer rates in cells with vertical planar electrodes, one of which evolves gases. The mathematical model employed either the k‐ε or the k‐l representation of turbulence. The predictions of the model were compared with experimental velocity measurements, carried out using a laser‐Doppler velocimeter, on a laboratory cell; semi‐quantitative agreement was obtained in the case of the k‐l model when the bubble size was used as an adjustable parameter. Crude comparisons could be made between mass‐transfer predictions and measurements of others.