Analysis and optimization of the electrohydrodynamic (EHD) flow with a wire-to-two-cylinder configuration for convective heat transfer

Abstract

Electrohydrodynamic (EHD) flow is a promising field, especially for gas pumping applications. The EHD flow could be produced by the formation of non-thermal plasma (NTP) on a surface with high curvature. In this study, an analytical model was employed, and the experiment was carried out with the configuration of a wire and two cylinders in an open space. The Townsend relation between electric signals was checked for the stable generation of corona discharge, and the empirical equation was employed to verify the relation between parameters, such as current, voltage, and momentum. In this process, the momentum of EHD flow can be expressed as a function of the design variables, so that the characteristics of the NTP pump can be estimated. The efficiency of the system could be determined from the experimental results. The optimal point obtained from the electrical and hydraulic characteristics showed an efficiency of 2.6%, which was 2 times larger than that of the NTP pump reported in previous works. Heat transfer experiments were also carried out for the cooling effect of EHD flow as a pump using a heat plate with constant heat flux, which was placed parallel to the cylinder electrodes. For various cylinder electrode heights and voltages, the heat plate was cooled by the EHD flow, and the temperature was measured using thermocouples. The cooling performance of the EHD flow was evaluated by comparison with the heat transfer coefficient of natural convection. The heat transfer coefficient and Nusselt number were calculated, and their correlation could be obtained. Additionally, an infrared thermal camera was used for spatial reduction, and the global temperature of the overall heat plate could be obtained.