Experimental Investigation of Hybrid Aluminum–Copper Exposed Electrodes for Thermal Hot Spot Reduction in DBD Plasma Actuators

Dielectric barrier discharge (DBD) plasma actuators have attracted increasing attention for anti-icing and de-icing applications due to their ability to combine surface heating and plasma-induced flow control. Their electro-thermal behavior is strongly influenced by exposed electrode material, geometry, and dielectric configuration, often leading to localized hot-spot formation and reduced operational stability. However, the impact of exposed electrode material and electrode thickness remains poorly understood, representing a significant gap in understanding the electrical and thermal response of these devices. This study presents an experimental electro-thermal investigation of DBD plasma actuators employing copper, aluminum, and hybrid copper–aluminum exposed electrodes. Copper and aluminum were selected as exposed materials because they present two contrasting electrical–thermal extremes. The actuators were tested using dielectric barrier thicknesses of 1 mm and 2 mm, considering both standard and enlarged (10 times) exposed electrode thickness. The electrical diagnostics show that aluminum electrodes promote stronger and more uniformly distributed microdischarges due to enhanced discharge initiation, but at the expense of increased power consumption. In contrast, copper electrodes exhibit lower power demand but lead to concentrated current density and localized thermal hot spots. Motivated by this electrical–thermal trade-off, a hybrid electrode was developed to combine the high electrical stability of copper with the discharge uniformity of aluminum. The hybrid configuration demonstrates intermediate power consumption and significantly improved thermal uniformity, effectively mitigating hot spot formation. These results highlight the importance of exposed electrode electrical properties in the electrical and thermal characterization of DBD plasma actuators and identify the hybrid configuration as a promising solution for future thermally driven ice-mitigation applications.