Plasma-Based Flow Control for Improved Aerodynamic Efficiency

Plasma flow actuators have emerged as an innovative solution for active flow control, offering unparalleled capabilities to enhance aerodynamic performance. These actuators employ a plasma discharge to generate an electrohydrodynamic (EHD) force, creating ionized regions that interact with airflow to improve boundary-layer stability, delay flow separation, and reduce drag. The plasma actuators consist of two electrodes separated by a dielectric material. A high-voltage AC input is supplied to the electrodes. When the alternating current (AC) amplitude is large enough, the air ionizes in the most significant electric potential region. Ionization forms ions and electrons. The ions move under the drive of an electric field and transfer momentum through collision with neutral gas molecules. In this paper, an experimental study on the laminar and turbulent boundary layers of a low-pressure turbine blade is conducted using dielectric barrier discharge plasma excitation. The results show that the plasma excitation's velocity increase near the wall is significant and long-lived. It can also enhance the performance of traditional control surfaces or the operational flight envelope of air vehicles by providing controls at flight conditions where conventional control surfaces are ineffective.