Romain Joussot

Thermal Characterization of a DBD Plasma Actuator: Dielectric Temperature Measurements Using Infrared Thermography

Active flow control by plasma actuators is currentl y under investigation in order to improve the aerodynamic performance of vehicles. One of these actuators consists in using a surface dielectric barrier discharge (DBD) by creat ing a non-thermal plasma at the dielectric surface. The plasma discharge induces a low-velocity airflow, the so-called “ionic wind”, which can be used to modify external flows. In this study, we focus on the description of the thermal effect of a DBD actuator in order to contribute to a better understanding of the mechanisms of interaction with the flow. The te mperature of the dielectric surface was first determined with the plasma on and secondly af ter switching off the discharge. The measurements were conducted for several amplitudes and frequencies of the applied voltage. The study comprised two parts: in the first, measur ements were performed in quiescent air, and in the second, the influence of an external bou ndary layer over the discharge on the dielectric temperature was investigated.

Negative Spark Leaders on a Surface DBD Plasma Actuator

Plasma actuators are currently under investigations in order to improve the aerodynamic performances of vehicles. Such devices induce airflow of few kilometers per hour called ionic wind. A previous study showed that ionic wind velocity is limited by a particular regime of the discharge where bright and long sparks appear. In this paper, we present some typical images of these spark leaders.

Modification of the Laminar-to-Turbulent Transition on a Flat Plate Using DBD Plasma Actuator

Active flow control by plasma actuators, usually ca lled ElectroHydroDynamic actuators, is currently under investigation in order to modify and control external flows. One of these actuators consists in using a surface dielectric ba rrier discharge by creating a non-thermal plasma at the dielectric surface. The plasma induce s a low-velocity airflow, the “ionic wind”, which adds momentum close to the wall. In this study, the ability of such an actuator to delay or promote the transition of a boundary layer developed along a flat plate is studied experimentally.

Transition control using a single plasma actuator

The aim of this study is to modify, by using surface plasma actuators, the laminar-to-turbulent transition location of a Blasius boundary layer developing on a flat plate mounted in an opened wind tunnel. Measurements of flow velocities were performed by hot wire anemometry. Results show that an actuator placed upstream the natural transition zone enables the promotion or the delay of the transition onset, depending on the location, the voltage amplitude, and the frequency of the high voltage electrical parameters.

ICCD Imaging of a Plasma Filament in a Circular Surface-Dielectric-Barrier-Discharge Arrangement

The development of plasma filaments in a single-side surface dielectric-barrier discharge is investigated. Morphological characteristics are presented for anodic and cathodic regimes. Intensified-charge-coupled-device pictures have been acquired at different specified times of the discharge. They show the time evolution of filaments, which appear about 100 μs before the beginning of each half period. Moreover, the correlation with current peaks underlines that filaments are not ignited simultaneously in our specific conditions.