Flow induced by an EHD gas pump with secondary emitting electrodes

Abstract

Flow induced by an electrohydrodynamic (EHD) gas pump in a circular tube, which has the primary emitting electrodes flush mounted evenly on the tube wall and the secondary emitting electrodes attached to a concentric ring, has been experimentally investigated for two different configurations with varied gap distance. Earlier studies have shown that the flow produced by the primary emitting electrodes alone has a velocity profile similar to a wall jet with higher velocities near the wall and smaller velocities at the core region. The main objective of the present study is to increase the volume flow rate by the addition of secondary electrodes. To this end, the secondary electrodes have been attached to a concentric ring at the same level of the primary electrodes. Two configurations (with either 4 or 8 secondary emitting electrodes) are considered. In addition, two gap distances between the primary and secondary electrodes are considered as well. Velocities are measured in both radial and angular directions and then integrated to obtain the volume flow rate. The results obtained are compared with those produced by the primary electrodes alone to give additional insight to the problem.