Airflow influence on the discharge performance of dielectric barrier discharge plasma actuators

In the present work, the effect of the airflow on the performance of dielectric barrier discharge plasma-actuators is investigated experimentally. In order to analyze the actuator's performance, luminosity measurements have been carried out simultaneously with the recording of the relevant electrical parameters. A performance drop of about 10% is observed for the entire measured parameter range at a flow speed of M = 0.145 (U_∞=50 m /s). This insight is of particular importance, since the plasma-actuator control authority is already significantly reduced at this modest speed level. The results at higher Mach numbers (0.4<M<0.8) reveal an even more pronounced reduction of about 30%. From the combined analysis, the conclusion is drawn that the decreasing electrical performance P_A correlates closely with the decreasing luminosity peak intensity Ĝ for increasing airflow velocities. Two non-dimensional scaling numbers are proposed to characterize and quantify the airflow influence. It is demonstrated that these numbers span a universal performance drop diagram for the entire range of investigated operating parameters.