Action of a pulsed DBD actuator on a slow jet

In the last 10 years, the ability of surface dielectric barrier discharges (DBDs) to modify subsonic airflows (on airfoils, cylinders and flat plate) has been demonstrated by several studies. In the present experimental work, a very fast pulse (50 ns) high voltage generator was used to realize an electrohydrodynamic actuator. This device consisted of a series of 12 elementary DBDs. The effects of this pulsed electric discharge on a round wall jet in still air placed tangentially to the wall (4 m/s) were measured with laser doppler anemometry (LDA) technique. Mean velocity profiles have shown that the jet was accelerated in the vicinity of the actuator by the induced ionic wind. Moreover, the fluctuating components of velocity and power spectral density demonstrated that the flow instabilities were amplified. Hence, the pulsed DBD actuator made the wall jet overall turbulent.