Retrieval of Flow-Field Temperature and Concentration of Low-Visibility Propellant Rocket Exhaust Plumes

摘要

Diagnostic procedures based on iterative Abel inversion have been developed and tested for retrieving both the particle- and gas-phase properties of low-visibility propellant rocket exhaust plumes. The required input data consist of transverse scans of the plume infrared radiance and transmittance at wavelengths in and just outside the gas emission band; data also include transverse scans of angular laser scattering efficiency at the off-band wavelength. From these data, retrieval can be made for the particle volume scattering and volume absorption cross sections, scattering phase function, particle temperature, gas temperature, and gas concentration. The diagnostics are limited to particle loading levels small enough to justify the use of the single-scattering approximation. Example applications are made to three plume models containing Al2O3/H2O, C/HCl, and ZrO2/H2O as the particle and gas phases. For all cases, accurate and unique retrieval of the flow-field properties from exact synthesized transverse data is demonstrated. (Author)