The effect of external flow velocity on the momentum transfer of DBD plasma actuators

Abstract

An experimental study is performed towards identifying possible cross-talk effects between DBD actuators and externally imposed flow. The actuator has been positioned in a boundary layer operated in a range of free stream velocities from 0 to 60 m/s, and tested both in the upstream and downstream configuration. Two experimental set-ups were tested. In the first measurement campaign the flow field and the plasma induced momentum has been measured using Particle Image Velocimetry from which the actuator momentum transfer was derived. In the second experimental campaign the DBD actuator was made stronger and the body force was measured directly with a load cell. Electrical measurements were also used for estimating the power consumption and the discharge formation has been visualized using an intensified CCD camera. Results show the measured force is practically constant over the range of considered wind speeds, with the same magnitude and opposite direction for the upstream and downstream configuration. The power consumption measured was also constant for different flow velocities and actuator configurations. This indicates that the external flow velocity does not have a significant impact on the momentum transfer of the actuator, seemingly confirming the commonly used assumption that the actuator’s body force is independent of the external flow.