Flows Generated by Electrohydrodynamic Gas Pumps with Different Electrode Orientations

Abstract

Numerical simulations have been performed to examine the flows inside a square channel produced by a two-stage electrohydrodynamic (EHD) gas pump with two electrode arrangements. The EHD pump has a pair of seven emitting electrodes flush mounted on two parallel walls at each stage. The flush-mounted electrodes produce corona wind similar to a wall jet that is mainly responsible for flow delivery. The pump is operated by a combination of three different voltages (24, 26, and 28 kV) for performance improvement. Because flow visualization is very challenging to implement in experimental study of EHD flows, very few results are available in the literature. As such, this study is specifically aimed at providing additional insight to the flowfield inside the channel through visualization of the numerical results obtained. Also, the overall effectiveness of the EHD gas pump is evaluated by the volume flow rate delivered as well as its power efficiency. It has been found that the power efficiency for the EHD pumps considered is higher than the conventional fans/pumps. Thus, they have a great potential for applications in thermal management. Particularly, they can be more energy efficient when they are operated by uneven applied voltages.