A comprehensive study was performed to explore the thermal characteristics of NS-dielectric-barrier discharge (DBD) plasma actuation over an airfoil/wing surface and evaluate the anti-/de-icing performance of NS-DBD plasma actuators for aircraft in-flight icing mitigation. While the fundamentals of thermal energy generation and heat transfer in NS-DBD plasma actuation over the airfoil/wing model were described in great details, a series of experiments were conducted to evaluate the effects of different environmental parameters on the heating efficiency of NS-DBD plasma actuators over the airfoil/wing surface. With the temporally-synchronized-and-spatially-resolved high-speed visualization and infrared imaging system, not only the transient thermal characteristics of NS-DBD plasma actuation over the airfoil/wing surface were revealed, but also the anti-icing performances of the NS-DBD plasma actuators were evaluated under different icing conditions, i.e. rime, mixed, and glaze. The impacts of incoming airflow velocity, air temperature, and angle of attack of the airfoil/wing model on the thermal characteristics of NS-DBD plasma actuation over the airfoil/wing surface were systematically investigated based on the measurement results. It was found that the thermal characteristics of NS-DBD plasma actuation over the airfoil/wing surface are closely coupled with the boundary layer airflow and the unsteady heat transfer process over the airfoil/wing model exposed in the frozen-cold airflows. The anti-icing performances of the NS-DBD plasma actuators under the different icing conditions were found to be varying significantly due to the variations of surface heating efficiency of the NS-DBD plasma actuators. The anti-/de-icing performance of the NS-DBD plasma actuators was found to be improved dramatically by increasing the operating frequency of the plasma actuators. The findings derived from the present study are very helpful to explore/optimize design paradigms for the development of novel plasma-based anti-/de-icing strategies tailored specifically for aircraft inflight icing mitigation to ensure safer and more efficient aircraft operation in atmospheric icing conditions.

Purpose: This paper aims to investigate the effects of a dielectric barrier discharge (DBD) plasma actuator (PA) qualitatively on aerodynamic characteristics of a 3 D-printed NACA 4412 airfoil model. Design/methodology/approach: Airflow visualization study was performed at a Reynolds number of 35,000 in a small-scale open-loop wind tunnel. The effect of plasma actuation on flow separation was compared for the DBD PA with four different electrode configurations at 10°, 20° and 30° angles of attack. Findings: Plasma activation may delay the onset of flow separation up to 6° and decreases the boundary layer thickness. The effects of plasma diminish as the angle of attack increases. Streamwise electrode configuration, in which electric wind is produced in a direction perpendicular to the freestream, is more effective in the reattachment of the airflow compared to the spanwise electrode configuration, in which the electric wind and the free stream are in the same direction. Practical implications: The Reynolds number is much smaller than that in cruise aircraft conditions; however, the results are promising for low-velocity subsonic airflows such as improving control capabilities of unmanned aerial vehicles. Originality/value: Superior efficacy of spanwise-generated electric wind over streamwise-generated one is demonstrated at a very low Reynolds number. The results in the plasma aerodynamics literature can be reproduced using ultra-low-cost off-the-shelf components. This is important because high voltage power amplifiers that are frequently encountered in the literature may be prohibitively expensive especially for resource-limited university aerodynamics laboratories.