Fluid–plasma bidirectional coupling: An experimental analysis of the reverse influence of fluid flow on plasma discharge

Surface dielectric barrier discharge (SDBD) plasma aerodynamic actuation flow control technology has broad potential to improve the aerodynamic performance of aircraft. The essence of the flow control mechanism is the bidirectional dynamic interaction between fluid and plasma. At present, plasma flow control research mainly focuses on the unidirectional disturbance of the flow field by plasma aerodynamic excitation, and the reverse influence of the fluid flow on the gas discharge plasma process has been considered less. Therefore, this paper builds an SDBD actuator discharge test platform in a low-speed wind tunnel to explore the influence of the fluid flow rate on the discharge characteristics of the SDBD plasma actuator. The experimental results show that with the increase in airflow velocity, the distribution area of the SDBD plasma shows a trend of spanwise elongation and transverse broadening. At the same time, the discharge current amplitude decreases, and the discharge frequency increases greatly. Compared with non-airflow conditions, in a 40 m/s airflow environment, the plasma distribution length increases by 130.8%, the width increases by 74.0%, and the discharge frequency increases by 666.7%. These experimental results rigorously validate the significant reverse effect of airflow on the plasma discharge process, while clearly revealing the bidirectional dynamic interaction between plasma excitation processes and fluid dynamics. This discovery highlights the necessity of reassessing plasma flow control strategies across different flow conditions, providing crucial guidance for optimizing plasma actuator design and formulating flow control strategies.