Study on the Influencing Factors of Flow Control by Plasma Excitation

This study explores the use of plasma excitation to control and modify shock wave structures in high-speed airflow, particularly addressing the challenge of shock wave interference in high-speed vehicles. The researchers developed a coupling analysis model based on phenomenological simulation methods to under-stand how high-speed airflow interacts with plasma. Experiments were conducted in a wind tunnel with a Mach number of 8, focusing on how different incoming airflow conditions, especially the enthalpy of the airflow, affect the effectiveness of plasma-based flow control. The study revealed that a higher ratio of excitation power to free stream power leads to more effective control over the airflow. Additionally, plasma flow control was found to be more effective in low enthalpy wind tunnels compared to high enthalpy conditions, even when the discharge energy was the same. The research also observed significant differences in the shape and development rate of shock waves induced by plasma jets under various enthalpy conditions. In low enthalpy, the induced shocks were more pronounced and propagated slower, while in high enthalpy, the shocks were weaker but moved faster. This indicates that the environmental conditions in which plasma jets are used play a crucial role in their effectiveness. Furthermore, the study noted that while there is a positive correlation between the energy of the plasma discharge and the control effect on shock waves, the duration of the control effect is not directly tied to the discharge energy. This suggests that the strength of the control depends on both the energy applied and its interaction with the airflow. The findings underscore the importance of understanding these factors for the application of plasma flow control in real-world, high-speed flight conditions. The research provides a valuable foundation for future studies and practical applications in aerospace, particularly in designing systems to efficiently manage shock wave interference in high-speed vehicles. In conclusion, this study highlights the potential of plasma technology in active flow control, offering significant insights into optimizing plasma-based actuators for improved aerodynamic performance in high-speed aircraft. The results emphasize the necessity of considering both power ratios and environmental conditions for the effective deployment of such systems in real-world scenarios.