Plasma-Radiofrequency Interactions Around Atmospheric Re-Entry Vehicles: Modelling and Arc-Jet Simulation

ABSTRACT

An aero-thermo-chemical model is developed to simulate the flowfield, including ionization, around atmospheric re-entry configurations, and its interactions with radio-frequency communication signals (e.g. GPS). The model is successfully validated against literature in-flight measurements of the electron number density, and then applied to the re-entry of recently proposed concepts of slender configurations. The advantages of using sharp and slender geometries for re-entry applications, with respect to radio communication problems, are analyzed and discussed.

In addition, an experimental test-bed in an arc-jet plasma wind-tunnel has been setup to reproduce on ground the plasmaradiofrequency interaction. The capability to duplicate on-ground the ionization levels encountered during re-entry has been successfully demonstrated. A numerical model of an Argon plasma jet in chemical and thermal non-equilibrium has also been developed, for numerical rebuilding of the experiments. Both electron number densities and electron temperatures have been successfully correlated, demonstrating the ability of arc-jet facilities, integrated with proper numerical tools, to correctly deal with problems of communication attenuation/black-out.

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