Numerical Simulation of Flow Separation Control Using Plasma Actuators

Abstract

The dielectric barrier discharge (DBD) plasma flow control technology is notable for its quick response and effective fluid control. It has attracted attention from many fields, including mechanics and aeronautics. This study employs the Suzen sophisticated volume force model to simulate complex plasma dynamics, using the Reynolds–Averaged Navier–Stokes equations by means of a density-based solver. For turbulence modeling, the k–ω SST model is adopted to capture turbulent phenomena, with the Roe method applied for discretization. The proposed numerical approach has been rigorously validated by analyzing challenging flow cases, such as flat plates and hump models. The flat plate simulation results align closely with the experimental flow velocity data, while the plasma-induced wake vortex over the hump model is significantly mitigated. Building on the RAE2822 airfoil, this investigation explores the aerodynamic behavior at various angles of attack, with and without plasma actuation. The aerodynamic response is further examined at various flight altitudes and airflow velocities following actuator activation. Findings indicate that the geometric profile influence on the airfoil’s aerodynamic properties is negligible upon actuator engagement or disengagement. As compared to an airfoil without plasma excitation, the actuated airfoil exhibits the enhanced aerodynamic traits. Notably, exciting at α = 2° optimizes outcomes by boosting the lift coefficient by 7.19% and reducing the drag coefficient by 8.45% when the free-stream Mach number is equal to 0.79. The aim of this actuation is to enhance lift and minimize drag while effectively mitigating boundary layer separation and diminishing surface vortices. Exploration of flight altitudes (H = 0.3, 2.3, and 4.3 km) revealed that the plasma actuator has a significant influence on the lift-to-drag ratios at lower altitudes, with the effects diminishing above 2.3 km. The plasma actuator is most effective in enhancing the lift-to-drag characteristics at a flight Mach number of 0.72 when flow velocities are analyzed. Thus, controlling the flight speed to maintain a constant angle of attack can significantly improve the aircraft performance. In light of these findings, incorporating the plasma flow control technology into airfoil design could be pivotal for enhancing the lift-to-drag ratio and overall flight performance of aircraft.