Influence of Coulomb forces on Fe3O4-H2O nanofluid thermal improvement in a cavity with moving wall is examined. The final formulas are solved via Control Volume based Finite Element Method. The influences of volume fraction of Fe3O4, supplied voltage and Reynolds number on the hydrothermal characteristics are considered. Results indicate that existence of electric field can alter the nanofluid flow style. As Coulomb force augments temperature gradient along hot wall enhances. Nusselt number enhances with augment of supplied voltage. (C) 2016 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.