Investigation of plasma actuator configurations for the dynamic heave-pitch motion of an airfoil through large eddy simulations

In the study of unsteady aerodynamics, controlling highly nonlinear flow structures caused by complex airfoil motions remains a significant challenge for the development of next-generation flight systems. This study investigates alternating-current dielectric barrier discharge-based active flow control on an airfoil with dynamically heave-pitch motion at a Reynolds number of 13 800, using the Open Field Operation and Manipulation framework for large eddy simulation-arbitrary Lagrangian–Eulerian. Many studies show that plasma-flow control for pure pitching motions has been thoroughly examined and has been described using 2 degrees-of-freedom (DOF) kinematics without plasma; the integration of active flow control into combined heave-pitch cycles remains unexplored. This study narrows a crucial gap by integrating and comparing spanwise segmented and linear configurations of plasma actuators on the airfoil's upper surface to control the complex vortex-surface interactions observed in 2-DOF kinematics. The numerical approach integrates a pimpleDyMFoam solver with a Smagorinsky–Van Driest subgrid-scale model. After the numerical simulation was completed, the results revealed that the spanwise segmentation of the plasma is highly controllable at key points: stall onset, maximum stall, and reattachment. Also, the lift coefficient (Cl) in the spanwise segmented plasma case is stabilized, with a 7.35% reduction, and the drag coefficient (Cd) is 10.74% of the baseline. Furthermore, a 54.28% increase in the minimum lift-to-drag ratio smooths out the risky force spikes that come with 2-DOF motion. In the end, this research shows that segmented plasma is a very promising option for balancing the unstable loads of bioinspired, agile flight systems.