Dual mitigation of aerodynamic heating and radio frequency blackout through gas injection in large-scale plasma wind tunnel

Abstract

Addressing the challenges posed by communication blackouts and aerodynamic heating during atmospheric entry is imperative to grant mission success and safety. To evaluate the effectiveness of film cooling in mitigating these issues, an arc-heated wind tunnel was used to generate high-enthalpy weakly-ionized flow. A model equipped with injectors for film cooling and containing an antenna was used. The wind tunnel was operated either using pure argon, or an argon-nitrogen mixture with similar thermodynamical properties; a little amount of nitrogen causes a significant reduction of the free electrons in the flow. For this reason, plasma effects such as communication blackout were observed only within the pure argon flow condition. The application of film cooling both reduced the surface heating rate and increased the communication strength between antennas. These findings demonstrate that the film cooling technique offers a viable approach to simultaneously addressing the two major challenges encountered during atmospheric reentry.