The plasma sheath surrounding a hypersonic vehicle will have a severe interference on the wireless communication signals and even interrupt the signals, threatening the flight safety. The plasma sheath is closely related to the vehicle's shape which indirectly affects the propagation characteristics of the radio waves. For understanding the influence of different aerodynamic shapes on the wave propagation, the EM wave propagation in the plasma sheath produced by aircraft, including blunt and pointed cone, is investigated. First, the commercial software COMSOL is used to calculate the flow field distribution under different flight conditions, generating the discrete model of plasma sheath. Then, according to the wave propagation theory in the plasma and using the Lagrange and Runge-Kutta methods, ray equations in the plasma sheath are solved numerically, which results in observing some new characteristics of wave propagation, such as waveguide behavior. The results show that, under the same conditions, the interference caused by the blunt vehicle is stronger than that by the pointed vehicle. These results can provide references for the design of hypervelocity aircraft, and further promote the study of related issues.
