Aerodynamic Quality Management for the NACA 23012 Airfoil Model using the Surface High-Frequency Discharge

The effect of the surface capacity HF discharge on airfoil flow-around has been studied in the situation when the oncoming flow velocity is $20$ m/s and the Reynolds numbers are $\text{Re} = 10^5$. The power delivered to discharge was modulated with a frequency of $3 \times 10^2$–$2 \times 10^4$ Hz, which corresponds to a Strouhal number of $\text{St} = 1.2$–$80$, and the average electric power $(W_{\text{av}})$ was $50$–$400$ W. It has been indicated that the aerodynamic drag decreased and the lift increased at stall and post-stall angles of attack when the HF dielectric barrier discharge was turned on. A nonstationary stochastic change in the $C_x$ and $C_y$ aerodynamic characteristics was observed at a stall angle in the $\text{St} = 4$–$10$ range of Strouhal numbers when the power was insufficient $(W_{\text{av}} \approx 100$ W$)$.