Modeling of the Operation of EHD Devices with the Working Medium of Complex Microstructure

Abstract

The model of a working medium of complex microstructure is used to calculate processes in a channel of one stage of an electrohydrodynamic (EHD) device. The flow of a multicomponent fluid consisting of neutral particles and a small admixture of two kinds of oppositely charged ions through a plane channel with dielectric walls is investigated. Two plane electrodes penetrable by the fluid and exerting no hydrodynamic drag force are placed in the cross sections of the channel. These electrodes and the space between them form a stage of an EHD device applied to increase the pressure in the medium. It is shown that the pressure drop and the total volume charge of the stage almost linearly depend on the applied voltage in a certain range; however, there is a critical value beyond which a further increase in voltage reduces the efficiency of the converter. This is due to the influence of injection of negative ions from the cathode, which grows with increasing field and causes redistribution of the volume charge in the interelectrode space.