Impact of ionization rate on the transmission of electromagnetic wave in realistic plasma
Wenchong Ouyang, Yanming Liu
Abstract
A self-consistent calculation model of hypersonic fluid and electromagnetic wave (EM) propagation around a vehicle was used for radio frequency (RF) blackout prediction. First, the plasma flow around the RAMC-II vehicle at an altitude of 61 km was calculated using the finite-volume method with a newly developed unstructured grid solver. The electron number density around the RAMC-II vehicle shows good agreement with the flight test data and NASA data. Then, the effect of chemical reaction ionization rate on the plasma flow is studied, which shows that the electron number density decreases with the decrease in the chemical reaction ionization rate. Finally, based on the influence of the chemical reaction ionization rate on plasma flow, the transmission properties of the electromagnetic wave in realistic plasma at different chemical reaction ionization rates were investigated. The numerical results show that the signal loss of EM waves decreases with the decrease in the ionization rate. The ionization rate is reduced by 25 times, and the electromagnetic wave signal loss is reduced by approximately 30 dB. Based on the study, a scheme to reduce the electron number density around the vehicle by reducing the ionization rate of the chemical reaction, thereby reducing the signal loss of the electromagnetic wave, can be considered to mitigate the RF blackout.