A Nanosecond Surface Dielectric Barrier Discharge Operating Under Altitude Conditions for Aeronautics Applications

The objective of this paper is to investigate the influence of environmental conditions on a nanosecond pulsed dielectric barrier discharge (NP-DBD). A test chamber where pressure and temperature can be changed to match with realistic altitude conditions has been used. Electrical and optical characterizations of the NP-DBD are proposed for pressure and temperature changes in range related to flow control applications. In particular, the influence of low pressure is investigated. The results indicate that a reduction in pressure leads to a more diffuse plasma layer to a more diffuse plasma layer and an enhanced propagation. The energy dissipated by the discharge increases with a reducing pressure. Regardless of the pressure level, the heat released by the NP-DBD leads to the formation of a pressure wave propagating at sound speed. A good correlation was found between the extension of the plasma layer and the planar part of the produced pressure wave. Similar electrical characterization has been conducted when the temperature is reduced, while the pressure is maintained at an atmospheric level. It was shown that temperature has the minor effect on the discharge characteristics, but lower is the temperature and lower is the deposited energy. In a final part, the influence of the altitude is investigated by studying the combined effects of pressure and temperature. It results that the pressure variation dominates the temperature influence. As a result, higher energy deposition is reported when the altitude is increased. The effect of changes in the pressure and temperature is interpreted as an effect of changes in the gas density. It is concluded that the gas density, N, is an important parameter for studying DBD under the altitude conditions. Indeed, quantities such as the plasma extent and the deposited energy scale with N-0.5. However, the gas density does not consider changes in the dielectric permittivity, which restricts the use of the gas density matching method to altitudes with moderate ambient temperature.