Electron Density Measurements in a Plasma around a Body in High Enthalpy Hypersonic Flow by means of Radar
Abstract
Aerodynamic heating around a body in high speed flows leads to ionization and finally to the generation of plasma. While macroscopic quantities like pressure and temperature are accessible using standard sensors, microscopic quantities such as local electron density suffers from uncertainties in numerical predictions due to the lack of respective sensors as reference. In high speed flows, however, these microscopic quantities determine local chemical reaction and ionization rates and thus affect, for instance, the surface heat flux through radiation or lead to black-out phenomena. Since plasma has unique frequency dependent (dispersive) electromagnetic properties governed by local electron density distributions, a frequency selective mono-bistatic radar1 approach can deliver vital information on plasma distributions by considering the reflection of microwaves. To reduce the aforementioned uncertainties a radar-based measurement technique for electron density distributions in hypersonic shock tunnels in combination with a coupled simulation approach is proposed. First experiments have shown that the approach is feasible. The purpose of the proposal is to mature the technique and to test its suitability for relevant research topics in the field of hypersonic aerothermodynamics. The present proposal aims to detect and study flow phenomena such as shock wave-boundary layer interactions at a compression ramp and the boundary layer state being either laminar or tripped using roughness elements.
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Feb 22, 2024
- Source ID
- FA86552317022
Entities
People
- Alexander Wagner
Organizations
- Air Force Office of Scientific Research
- United States Air Force