Flow characteristics of a single stage EHD gas pump in circular tube

• Flows induced by EHD gas pumps in circular pipes are experimentally evaluated.
• An EHD gas pump is found to be more effective when operates at small voltages.
• A small-diameter EHD pump is more effective than that of a large diameter.
• Volume flow rate increases with applied voltage but approaches an asymptotic value.

Characteristics of flow induced by electrohydrodynamic (EHD) gas pumps in circular pipe have been experimentally evaluated. Two tube diameters (61.8 mm and 127.8 mm) and two electrode gap distances (25 mm and 50 mm) have been considered. The gas pumps use eight evenly spaced emitting electrodes which are flush mounted on the tube wall. As such, flows induced by the pumps have a profile with a higher velocity near the wall and a lower velocity at the tube center. Experiments are conducted using positive corona discharge with voltage varying from 17.5 kV to 30 kV. The results show that the volume flow rate increases with the applied voltage but approaches an asymptotic value before sparkover takes place. From the present results, several important implications for the practical engineering applications are presented.