Design and Application of Filtered Rayleigh Scattering Experiments for Mixing Studies of New Strut Injectors for Scramjets

摘要

The description of the setup and experimental methodology used to quantify the local mixing of a helium-air mixture with the non-intrusive laser based Filtered Rayleigh Scattering (FRS) technique in a Mach 2.5 vortical flow is presented. Of particular interest is the effect of the imposed vortex dynamics on the degree of mixedness of the two constituent mixture components in the region of the mutually interacting co-rotating vortices generated by a strut injector specifically designed for the study of multiple vortex interactions in supersonic flow. The application of the FRS technique in such highly complex vortical flows, however, is not straightforward. Thus, detailed preliminary experimental characterization of all subsystems of the measurement is required along with a methodical experimental design procedure in order to achieve consistently successful measurements that are meaningful and relevant. All aspects of the experimental design and methodology will be presented, beginning with the necessary theoretical background of the FRS procedure and concluding with the preliminary results and supporting evidence showing the proper design of the mixing experiments.