Wire-rod type electrohydrodynamic gas pumps with and without insulation cover over corona wire

The effect of an insulation cover on a corona wire for a wire-rod type electrohydrodynamic (EHD) gas pump was experimentally investigated and one-dimensional cross sectional averaged analyses were performed. The insulation cover over the corona wire causes a fluctuation of the discharge current, resulting in fluctuations of the EHD gas flow. The insulation cover also changes the EHD force distribution, which is the product of an electric field and ion charge density. The EHD force concentrated at the center of the flow channel, and was directed toward the rod electrode in a straight line. Thus the rod electrode supposed to become a significant disturbance to the flow. The flow velocity fluctuations and the modified distribution of the EHD force with the insulation cover enlarged the flow head losses, and eventually resulted in smaller flow velocity than that without the insulation cover over the corona wire.