Light propagation characteristics of turbulent plasma sheath surrounding the hypersonic aerocraft**Project supported by the National Natural Science Foundation of China (Grant No.61431010).

Abstract

The characteristics of light propagation through turbulent plasma sheath surrounding the hypersonic aircraft have been studied. The turbulent flow fields around a hypersonic aircraft are given by using the Navier–Stokes (NS) equations and k–ε turbulence model. Based on the distribution of flow field, refractive index and density of the plasma sheath for a blunt cone are discussed with different flight velocities and altitudes. The refractive index is mainly influenced by the electrons in the turbulent plasma sheath. The influence of different velocities and altitudes on the features of light propagation in the turbulent plasma sheath is analyzed. The results show that as the flight speed increases or the flight altitude decreases, the refractive index fluctuation becomes larger. It is also found that the refractive index fluctuation varies with the incident wavelength. This study shows how the characteristics of an optical beam propagating through plasma sheath are affected by the incident wavelength, flight velocities, and altitudes.