Plasma Effects on Electromagnetic Wave Scattering in Suborbital Hypersonic Flight

This paper investigates the impact of plasma generated by a suborbital hypersonic vehicle on electromagnetic wave scattering. Hypersonic flight presents unique challenges due to the complex physical phenomena involved. The high speeds of hypersonic vehicles result in the transfer of kinetic energy to the air through a detached shock wave, leading to heating, compression, and chemical reactions within the flow field. Under certain conditions, ionization phenomena occur, generating a plasma field around the aircraft. This study focuses on calculating the radar cross-section (RCS) of a hypersonic glide vehicle (HGV) at a Mach number of 15 and a suborbital altitude of 40 km to understand how the plasma field affects electromagnetic wave propagation and scattering. Computational Fluid Dynamics (CFD) is employed to determine plasma properties such as the electron plasma frequency, collision frequency, and permittivity. Two approaches – an approximate asymptotic method based on Ray Tracing and a Full-Wave method using Finite-Difference Time-Domain (FDTD) – are utilized to assess the impact of the plasma envelope on radar response. The results provide valuable insights into the interaction between the hypersonic plasma field and electromagnetic waves.