An experimental study was conducted to evaluate the anti-icing performance of NS-DBD plasma actuator under the conditions of airflow speed U = 65 m/s, ambient temperature T = −10 °C, liquid water content LWC = 0.5 g/m3, mean-volume diameter MVD = 25 μm, mainly to clarify the effect of pulse frequency and voltage amplitude of actuation on anti-icing performance. A NACA0012 airfoil model with a chord length of c = 280 mm was used in the tests. The NS-DBD plasma actuator was mounted at the front part of the airfoil. A FLIR infrared (IR) imager and CCD camera were used to record the anti-icing process of the NS-DBD plasma actuator. Two typical discharge conditions were selected for the anti-icing experiments. The first was HV-LF discharge, corresponding to discharge under higher voltage amplitude with lower pulse frequency; the second was LV-HF discharge, corresponding to discharge under lower voltage amplitude with higher pulse frequency. Results reveal that NS-DBD is a very promising method for anti-icing. With the same power consumption, the LV-HF discharge shows a better anti-icing performance compared to HV-LF discharge under the same icing conditions. In view of pulse duration and duty circle, combined with heat dissipation, it is suggested that there is a threshold frequency, corresponding to the voltage amplitude of electric actuation signal and the incoming flow condition, to achieve effective anti-icing performance.

Plasma flow control (PFC) is a promising active flow control method with its unique advantages including the absence of moving components, fast response, easy implementation, and stable operation. The effectiveness of plasma flow control by microsecond dielectric barrier discharge (µs-DBD), and by nanosecond dielectric barrier discharge (NS-DBD) are compared through the wind tunnel tests, showing a similar performance between µs-DBD and NS-DBD. Furthermore, the µs-DBD is implemented on an unmanned aerial vehicle (UAV), which is a scaled model of a newly developed amphibious plane. The wingspan of the model is 2.87m, and the airspeed is no less than 30m/s. The flight data, static pressure data, and Tufts images are recorded and analyzed in detail. Results of the flight test show that the µs-DBD works well on board without affecting the normal operation of the UAV model. When the actuators are turned on, the stall angle and maximum lift coefficient can be improved by 1.3 • and 10.4%, and the static pressure at the leading edge of the wing can be reduced effectively in a proper range of angle of attack, which shows the ability of µs-DBD to act as plasma slats. The rolling moment produced by left-side µs-DBD actuation is greater than that produced by the maximum deflection of ailerons, which indicates the potential of µs-DBD to act as plasma ailerons. The results verify the feasibility and efficacy of µs-DBD plasma flow control in a real flight and lay the foundation for the full-sized airplane application.

Icing and stalling on the surfaces of aircraft wings endanger flight safety. In this work, the research object is a nanosecond pulsed dielectric-barrier-discharge plasma actuation unit with distributed layout, and the aerodynamic performance of aircraft wing surfaces under icing and stalling conditions is improved by changing the plasma-actuation electrical parameters. Actuated under low voltage and frequency, the unit acts as a sensor to judge icing according to the change in electrical parameters. Actuated under high voltage and frequency, the discharge is severe and generates a large amount of heat, giving rise to an anti-icing unit; anti-icing is carried out through distributed-layout plasma actuation, forming modulated ice with evenly spaced distribution, which acts as a vortex generator and lessens the deterioration of aircraft aerodynamic performance under icing conditions. Actuating under high voltage and low frequency enables flow control, delays stalling, and increases lift. The different plasma-actuation functions are realized by connecting multiple units, which offers improved aircraft survivability in complex weather conditions.

No abstract

No abstract