Electrohydrodynamics (EHD) is the study of flow field induced by an electric field. The concept behind EHD is to transform electrical energy into kinetic energy. The induced kinetic energy can then be utilized for many applications such as chip-integrated cooling, drying in the food industry, reducing drag of aircrafts, spraying of dielectric material for printing, controlling particulate matter emissions as well as EHD thrusters and pumping. The focus of the present study is the use of EHD to induce flow in various channel configurations. The operation principle of an EHD pump is based on the interaction among electrically charged particles inside the dielectric fluid and their migration to the grounded plate. Corona discharge, produced by applied high voltage difference, is an electrical discharge brought on by the ionization of fluid surrounding the electrodes. For the current work, this applied voltage to the electrode is in the order of 10–30 kV generated by a DC power supply while the resulting electric current generated is very small in the order of μA to mA. EHD pumps are becoming more attractive for industrial application nowadays due to the lack of moving parts, simple and compact design with light structural weight as compared to conventional pumps or cooling fans. In addition, there is less operating noise and no vibration during the operation of EHD pumps.
The main focus of our present work is to perform an experimental study to determine the induced flow rate at different applied voltages using various channel and wire electrode configurations. The basic experimental setup consists of an EHD pump test section, a high-voltage power supply, an air velocity transmitter and a data acquisition system. EHD pump test sections with different geometries of channel (e.g., circular, square and rectangular channels with the same cross-sectional area) along with different wire electrode configurations were constructed and tested. Measurements were taken from the corona threshold voltage to the sparkover voltage. The objective of the present study is to evaluate various designs of EHD pumps by comparing the EHD pumping efficiency.
