The development of compact propulsion systems for nano and micro satellites is nowadays a growing research topic. Actually, the availability of low cost materials able to withstand space operation is now becoming widespread technology. This democratization on the access to space was not followed with a corresponding availability of critical propulsion technologies. However, the availability of propulsion systems for this class of satellites will provide them with new possibilities in what relates to mission profiles. In the present work an electrospray will be analysed, in particular the flow in the nozzle. This flow is controlled by a mix of pressure and electrostatic field. A full EHD (electrohydrodynamics) computational model is developed that is integrated in a classic CFD code using user specified functions. The proposed computational model was able to compute the flowfield for the electrospray test case under consideration. A benchmark against experimental results, by comparing spray thruster droplet size, concluded that the numerical model can predict their size within an error of 5%.