AIAA-2005-565-450Acoustic Testing of the dielectric barrier(3)

推进器的声波特性

Front ViewSide View1.22 mAcoustic sensorAcoustic sensor1.83 m 1.22 m Non-reflective booth Plasma Actuator Plasma Actuator’s standAngle of rotation (θ)Plasma actuator StandFigure 2: Diagram of the arrangement used for the first set of measurementThe second set of acoustic experiments was conducted in a large room with sound absorbing material covering the top half of the walls and the ceiling. The actuator was placed on one end of a rod with the microphone placed at the other end of the same rod one meter apart. The rod (with actuator and microphone) was connected to a tripod and elevated one meter above the floor. This set up is shown in figure 3.Figure 3: Arrangement used for second set of measurementsB. DBD plasma actuator description For all of the measurements reported here the electrodes were made of copper foil tape, 25 cm long and 1 cm wide for the upper electrode, and 3 cm wide for the lower electrode. For most of the measurements ordinary pane glass (approximately 30x8 cm) was used for the dielectric material and either thin glass epoxy or Kapton tape for the substrate material (Figure 1). The actuator was placed on a stand which could be rotated about the long axis of the actuator from 0 to 180 degrees. Five and ten degree increments in the angle, θ, were used. Figure 4 shows the actuator placement with respect to angle (the microphone is at the outer edge of the polar plot).3 American Institute of Aeronautics and Astronautics