Designing and computer engineering of EHD devices is hindered by the lack of data on electrophysical parameters-mobility and injection function. The injection function describes the process of ion formation at the electrode surface. It is commonly believed that for a fixed electrode material-liquid pair, the injection function depends only on the local electric field strength and is independent of the electrode configuration. Therefore, the work investigates the dependency of injection function on electrode geometry. Unique plane - six wires - plane electrode configuration was used as an experimental cell. The experimental study and the computer simulation of integral current characteristics are involved. Electric current was measured by so-called dynamical current-voltage characteristics (DCVCs). The computer simulation model solves the complete set of EHD equations using the COMSOL Multiphysics software package. The data are analyzed and interpreted in terms of the degree of conformity between the experiment and simulation.