Studyofanatmosphericsurfacebarrierdischargeactuatorusing a nanosecond rising high-voltage power supply Rabat H. 1 , Pons J. 2 , Hong D. 1 , Weber R. 3 , Leroy A. 3 1 GREMI, UMR6606, CNRS/Université d’Orléans, 14 rue d’Issoudun, BP 6744, 45067 Orléans cedex 2, France 2 EPEE FR776 CNRS, c/o GREMI, 14 rue d’Issoudun, BP 6744, 45067 Orléans cedex 2, France 3 PRISME, UPRES 4229, Université d’Orléans, 8 rue Léonard de Vinci, 45072 Orléans cedex 2, France 1. Introduction Abstract: In the field of flow control by plasma actuator, an original high-voltage power supply has been developed to provide a nanosecond rising followed by millisecond decay. With this device, a 15 kV discharge on a polymer dielectric barrier can be obtained with a rise time of about 30 nanoseconds. A slow decay in the millisecond range is controlled by resistor/capacitor loads connected to the actuator. This particular discharge was characterized by the electrical measurements (current and voltage) as well as by fast imaging usingan intensified camera. Studies on the action of such discharge in ambient air have also been carried out by Laser Doppler Velocimetry, by differential pressure measurement (Pitot tube) and by Mach-Zehnder interferometry. In particular, velocity measurements confirmed a higher production of ionic wind in the first half part of negative phase compared to the positive one of a “sinusoidal” signal. In the same way, the study of the nanosecond part has revealed differences between negative and positive pulses. Moreover, the interferometric diagnostic shows a supersonic propagation of shock wave and allows estimation of pressure variations induced by this one. Keywords: plasma actuator, nanosecond pulse, imaging, velocimetry, interferometry A plasma actuator consists in using a discharge on a profile to interact with the boundary layer ofan airflow to modify its properties. Since the early works of Roth’s group , many researches have been made to optimize the process from its design to its power supply. Most studies have concerned sinus-driven dielectric barrierdischarges with voltage rise times in the millisecond (ms) range, for which the generation of ionic wind is believed to be the main process in plasma/flow interaction. In recent years a broadening interest has aroused for fast rise pulses in the nanosecond (ns) range, following the publication of Starikovskii et al.  who demonstrated that plasma interacts with the ambient medium by the generation of a shock wave. The present paper focuses on a DBD actuator where the effects of ns and ms ramps are combined in a single pulse allowing for the generation of both a shock wave and ionic wind. For this, an original power supply has been built and different diagnostics have been used to both characterize the shock wave pressure front and the ionic wind velocity field. A specific interest has been carried on the influence of the voltage pulse polarity. 2. Experimental set-up 2.1. The actuatorand its power supply Our plasma actuator is a multilayer of polyester/polyimide strips and copper tape. A side view of the actuator can be seen on Figure 1 (see  for more information). The configuration used has 3 mm gap between the electrodes and a useful length of L=70 mm. Plasma formation on one side is prevented with a dielectric strip stuck onto the surface facing the edge of the corresponding electrode.