Prediction Performance of Blackout and Plasma Attenuation in Atmospheric Reentry Demonstrator Mission

Abstract

A numerical simulation model that combines the plasma flows and electromagnetic waves around a reentry vehicle during atmospheric reentry was developed to evaluate the radio frequency blackout and plasma attenuation. The physical properties of the plasma flow in the shock layer and wake region were obtained using a computational fluid dynamics technique. The electromagnetic waves were expressed using a frequencydependent finite-difference time-domain method with the plasma properties. Combined simulations were performed for the atmospheric reentry demonstrator of the European Space Agency at various altitudes based on reentry orbit data. The electromagnetic wave behaviors around the vehicle during atmospheric reentry were investigated in detail. Moreover, a parametric analysis with different ionization reaction models was performed. It was confirmed that the vehicle is surrounded by the plasma and the propagation of the electromagnetic waves is prevented at high altitude. Then, the plasma is dissipated, and the propagation recovers at low altitude. Validation of the simulation model was performed based on the plasma attenuation history of the experimental flight data. A comparison of the measured and predicted results showed good agreement. It was concluded that the combined simulation model could be an effective tool for investigating the radio frequency blackout and the plasma attenuation of radio wave communication.

Advanced validation of CFD-FDTD combined method using highly applicable solver for reentry blackout prediction

“…A formulation for the thermochemical non-equilibrium plasma flow during the aerodynamic heating was constructed, and its numerical implementation was achieved using the high-enthalpy flow simulation code RG-FaSTAR, which was developed according to the fast unstructured CFD solver "FaSTAR" [13] manufactured by JAXA. For an electromagnetic-wave simulation in plasma around reentry vehicle, the FD2TD method [8,12] was used. The distributions of plasma properties obtained by the flow solver were transposed on the computational domain for the electromagnetic-wave simulation, and the behaviour of electromagnetic waves in plasma around the reentry vehicle was clarified.…”

“…Because the FD2TD method with the first Drude dispersion used in the present study was formulated by Takahashi et al [8,12], physical and analytical models are briefly described in this section.…”

“…Takahashi et al [12] validated a model that combined CFD and FD2TD for the atmospheric reentry demonstrator (ARD) of the European Space Agency (ESA). However, because the angle of attack and the configuration of the ARD were not perfectly reproduced owing to the limitations in the flow field solver and grid generation, the combined model was not suitably validated.…”

Numerical Analysis of Radio Frequency Blackout for Atmospheric Reentry Vehicle Using CFD-Cem Combined Method

“…As mentioned above, however, this RF blackout was not observed in communication between ESA ARD and the TDRS using a link frequency of 2.267 GHz during atmospheric reentry. Uncertainties in chemical reaction models used in this analysis model causes this discrepancy, as pointed out by Takahashi et al [4]. At an altitude of 60 km, wave propagation recovers from the RF blackout, while strong attenuation and reflection in the plasma wake are caused by the recompression gas region.…”

“…In particular, the frequency-dependent finite-difference time-domain (FD2TD) method [1] has also been an effective tool for simulating electromagnetic waves in a frequency-dependent medium [2]. An analysis approach to predict RF blackout and plasma attenuation for a reentry vehicle, based on a method combining CFD and CEM, has been suggested by Takahashi et al [3,4,5].…”