Low electron density channel revealed in the plasma layer of hypersonic vehicle under a novel magnetic control

Abstract

The "communication blackout" occurs during the re-entry of hypersonic vehicles, that is, the electromagnetic wave cannot pass through the plasma sheath due to high electron density formed around the vehicle, which has drawn much attention but has not yet been solved. In this paper, a novel magnetic control approach is proposed, in which a periodic magnetic field is applied near the head of the aircraft. Based on the magnetohydrodynamic simulation, a low electron density channel across the plasma sheath of vehicle under the magnetic control is revealed for the first time, which probably make Ka-band electromagnetic wave pass through. We also find that the reason for the low electron density channel, is the variation of vortex structure in the plasma flow near the wall, by the electromagnetic force exerted on the flow. Furthermore, the optimal magnetic field frequency for generating the low electron density channel is obtained. These findings will be of significant benefit to the solutions for the communication blackout problems.