Application of an Integrated Flow and DBD Plasma Actuation Model to a High-Lift Airfoil: Part II — LES
A numerical study is conducted to explore the effect of a single dielectric barrier discharge (SDBD) plasma actuator for controlling a turbulent boundary layer separation on a deflected flap of a high-lift airfoil at a chord-based Reynolds number of 240000. An integrated numerical model consisting of a DBD electro-hydrodynamic (EHD) body force model and computational fluid dynamics (CFD) package called NavyFoam is employed in this study. The EHD body force is calculated by solving the Partial Deferential Equation (PDE)-based electrostatic equations for electric potential due to applied voltage and net charged density due to ionized air. The electric potential equation, the net charge density equation, and the flow equations are solved in separate computational domains. Comparison of current computational results against experimental data indicates reasonable agreement between the two studies for the baseline flow as well as controlled cases using two AC waveforms including sine and pulse-amplitude-modulated sine with different modulation frequencies. Performance of the actuator is also examined for the square and pulse AC waveforms. It is found that at the experimental conditions, the pulse-amplitude-modulated sine waveform provides the most lift enhancement in comparison with other waveforms used in this study, despite the least power input that it requires to operate. The effect of the input voltage amplitude on the performance of the actuator is also examined for the sine and pulse-amplitude-modulated sine waveforms. It is shown that beyond a critical voltage, the sine wave is more effective in improving the aerodynamic performance of the airfoil than the other waveform.