エアフィルム効果を用いた通信ブラックアウト低減化メカニズムの解明

抄録

During the atmospheric reentry phase, the communication between a vehicle and a ground station is interrupted. This phenomenon is called reentry blackout. A strong shock wave in front of the capsule can cause aerodynamic heating and ionize the gas. This plasma can block the propagation of electromagnetic waves emitted from its surface. It is necessary to reduce the number density of electrons near the capsule to mitigate the communication blackout. We focused on a new mitigation approach, which is the effect of air film. Cold gas injected from the surface forms a thin heat insulating layer. Electromagnetic waves can propagate inside the layer because of the low degree of ionization. In this study, we investigate the blackout mitigation effects using computational fluid dynamics (CFD) at a large-scaled arc- heated wind tunnel. The computational results indicated that injection gas forms the air film and works as a propagation path of the electromagnetic waves.