Airflow control by non-thermal plasma actuators

Active flow control is a topic in full expansion due to associated industrial applications of huge importance, particularly for aeronautics. Among all flow control methods, such as the use of mechanical flaps, wall synthetic jets or MEMS, plasma-based devices are very promising. The main advantages of such systems are their robustness, simplicity, low power consumption and ability for real-time control at high frequency. This paper is a review of the worldwide works on this topic, from its origin to the present. It is divided into two main parts. The first one is dedicated to the recent knowledge concerning the electric wind induced by surface non-thermal plasma actuators, acting in air at atmospheric pressure. Typically, it can reach 8 m s^-1 at a distance of 0.5 mm from the wall. In the second part, works concerning active airflow control by these plasma actuators are presented. Very efficient results have been obtained for low-velocity subsonic airflows (typically U_∞ <= 30 m s^-1 and Reynolds number of a few 10⁵), and promising results at higher velocities indicate that plasma actuators could be used in aeronautics.