A computational fluid dynamics based hydrodynamic model was developed for stationary hemispherical electrode under jet impingement. Reduction of ferricyanide was investigated both at the disk and the hemispherical electrode underjet impingement. Impedance results suggested a presence of conduction porous layer for experiments conducted in I M NaOH as supporting electrolyte with dissolved oxygen. This film was observed in electron and optical micrographs. The numerical simulations and the observation of non-uniform deposition on the hemispherical electrode confirm the presence of boundary-layer separation on the stationary hemispherical electrode under a submerged impinging jet. (c) 2005 Published by Elsevier Ltd.