Investigation on the ultraviolet spectral radiation characteristics of two-phase flow plume based on OH and alumina particles.

Abstract

Ultraviolet detection has advantages over radar and infrared detection, such as low background radiation and high resolution. The UV spectral radiation characteristics of exhaust plume are of extremely great research significance as the main parameters for aircraft detection. We used the BEM-2 two-phase flow plume as the object of study, calculated the scattering characteristics of alumina particles and the UV absorption coefficient of OH in the plume based on the MIE theory and the line-by-line integration method, established the UV radiation transfer model of aircraft plume under gas-solid coupling, simulated the UV spectral radiation characteristics of the plume, and compared them with experimental results. The results show that due to the drastic changes of temperature and pressure at the Mach and non-Mach disks in the plume, the value of OH absorption coefficient fluctuates up and down along the axial direction with the position of the Mach disk; at 261nm, 282nm, and 306nm, the spectral radiation intensity of alumina particles accounts for approximately 96%, 85%, and 73% of the total spectral radiation intensity of the plume, respectively, which are much higher than the proportion of OH gas spectral radiation intensity, but in the infrared wave band, the influence of particle scattering characteristics on the spectral radiation intensity of the plume is much lower compared to the UV wave band; the overall radial range of the UV spectral radiation intensity of the plume is relatively narrow and its tail exhibits a converging shape, showing a good consistency with the experimental results.