Extended Quantitative Fluorescence Imaging for Multicomponent and Staged Injection into Supersonic Crossflows

Abstract

The fluorescence ratio technique for processing planar laser-induced fluorescence data was extended for quantitative imaging of the injectant mole-fraction and density in multicomponent and multiinjection configurations in a nonreacting supersonic mixing flowfield. The method was experimentally validated in a mixing flowfield formed by single or staged sonic transverse injection into a Mach 2.0 supersonic air stream. Gaseous helium and air were used as injectants. Injectant mole-fraction distributions obtained by the present method were confirmed by comparison with gas-sampling data. Density distributions were validated with the oblique shock relation. The new method worked well for the multistaged injection configuration. Phase-locked measurement for the pulsed secondary injection was also tested. Results demonstrated the applicability of the new method to the pulse injection as well.