Non-equilibrium plasma distribution in the wake of a slender blunted-nose cone in hypersonic flight and its effect on the radar cross section

This paper presents numerical results in hypersonic aerothermodynamics, a critical field within aerospace engineering, traditionally focusing on reentry capsules and more recently, slender hypersonic vehicles. While capsules typically undergo near-field analysis to assess heat flux and pressure distributions for Thermal Protection System sizing, slender bodies demand additional attention to wake dynamics due to plasma presence. Plasma can significantly affect the Radar Cross Section (RCS) of these vehicles, which require tracking during flight due to their maneuvering and sustained flight capability. Utilizing Computational Fluid Dynamics tools, we explore plasma distribution around a slender blunted cone, considering altitudes and Mach number regimes that may characterize gliding or sustained atmospheric hypersonic flight, emphasizing its impact on RCS. Our study integrates an aerothermodynamic model incorporating non-equilibrium relaxation equations for gas composition and energy. By evaluating characteristic plasma quantities, we underscore the importance of wake plasma for subsequent electromagnetic wave analysis, crucial for understanding RCS. Furthermore, we highlight the necessity for collaborative efforts between Computational Fluid Dynamics (CFD) and Computational Electro-Magnetics (CEM) disciplines to address this challenging interdisciplinary problem.