The influence of electron injection from the aluminium electrode into organic liquid crystalline film, comprising the polar molecules, such as 4-n-pentyl-4'-cyanobiphenyl, on the orientational relaxation process is investigated. The numerical study of the system of hydrodynamical equations that includes both director reorientation and fluid flow, excited by that reorientation, for number of dynamic regimes has been carried out. It is shown that the relaxation process of the director (n) over cap to its equilibrium position (n) over cap (eq) is sensitive to electron injection from the metal electrode into organic dipolar film, whereas, the effect of backflow on that process is vanishingly weak. (C) 2007 Elsevier B.V. All rights reserved.