Effects of Orientation with Respect to Gravity for a Wire-Plate Convergent Angle Electrohydrodynamic Gas Pump

Electrohydrodynamic (EHD) phenomena have been shown to enhance heat transfer in a variety of heat transport designs including capillary pumped loops for extraterrestrial nuclear applications. Previously, EHD enhancement has been shown to improve the heat transport of experimental CPLs. Further enhancement with the addition of EHD gas pumps to the vapour phase requires EHD gas pump phenomena and performance to be characterized with respect to gravity to determine the expected enhancement from this arrangement in zero and microgravity environments. In this paper an EHD gas pump is oriented with gravity (inverted), 90° to gravity (horizontal) and against gravity (vertical) to determine the effect gravitational and buoyancy forces have on the flow and heat transport of EHD gas pumps. The flow and temperature profiles of the pump at the outlet are presented to demonstrate the orientation effect gravity and buoyancy imposes on EHD gas pumps. The EHD number is calculated and presented. The paper determines that there is a noticeable orientation effect at lower applied voltages due to the heating effects causing recirculation in the flow being reduced with the aid of buoyancy forces. However, the effect is less noticeable at higher applied voltages due to the stronger EHD forces.