Performance of an electrohydrodynamic gas pump fitted within a nozzle

Abstract

In this study, an EHD gas pump fitted within a conical nozzle is examined for three diameter ratios (DR = 1/2, 1/3, and 1/4). It has been tested for an applied voltage ranging from corona threshold up to sparkover. The results are critically examined to reveal the velocity profile of the corona jet at the downstream of the pump exit as well as the relation between the pump performance and diameter ratio. It has been found that three nozzle configurations have their own characteristics and performs differently under various conditions. A pump with a diameter ratio of 1/2 performs the best in maintaining a velocity profile that can extend the longest distance downstream of the pump while a pump with a diameter ratio of 1/4 can produce the highest velocity with the smallest increase in corona current. The maximum performance of 3 L/min/W is achieved by the pump with a diameter ratio of 1/2 operating at 15 kV. It is found that the flow and electric characteristic are not linearly dependent on the diameter ratio of the nozzle. As such, the design of an EHD nozzle gas pump for a specific application needs to consider an optimal combination of these parameters.