Towards Active Flow Control by Means of Plasma Actuators

The transition from laminar to turbulent flow in boundary layers significantly affects aerodynamic performance, drag, and fuel efficiency in aerospace applications. This study presents a numerical investigation into the use of Dielectric Barrier Discharge plasma actuators as an active flow control method to delay transition and reduce drag. A physics-based body force model based on the Shyy formulation was implemented via User Defined Functions in ANSYS Fluent to simulate plasma actuation effects. A series of simulations were conducted on a flat plate configuration using the transition SST model to validate baseline transition behavior against NASA benchmark data. Parametric studies were then performed to assess the influence of key actuator parameters, including electric field strength and electrode positioning, on boundary layer stability and transition onset. The results indicate that in turbulent intensity of 0.03%, activating DBD Plasma actuators promotes transition in boundary layer and even changing actuator position or electric field strength won’t be helpful. At turbulent intensity of 1%, actuators were able to delay boundary layer transition. In turbulent intensity of 5%, actuators were unable to have a significant effect on boundary layer transition. To identify optimal actuation configurations, a Multi-Objective Genetic Algorithm (MOGA) was employed. Actuator electric field strength and position were input variables for this optimization while intermittency selected as output function. Further enhancement was achieved by investigating a dual-actuator configuration, demonstrating improved flow control through combined momentum injection. The study confirms that properly tuned plasma actuators offer a viable AFC strategy for aerodynamic optimization. The findings contribute to the design of more efficient actuator configurations for practical integration in aerodynamic systems.