Scalar Spatial Correlations in a Supersonic Mixing Flowfield

摘要

Single-time two-point spatial correlations of injectant concentrations in the supersonic mixing flowfield producednby a sonic transverse injection of air into a Mach 2.0 supersonic airstream were investigated using acetone planarnlaser-induced fluorescence data. Side-view and end-view contour maps were obtained in several planes toncharacterize the turbulent structure and three-dimensionality of the mixing flowfield. The correlation mapsnindicated an organized large-scale structure in the upper region of the jet. The side-view correlation maps revealednthat the shape of the large dominating structure was elliptic and that itsmajor axis turned frombackward-leaning tonforward-leaning as the reference point of correlation moved downstream. The end-view correlation maps showednthat the instantaneous jet plume appeared by turns either in the top or in the lower sides of the time-averagedninjectant plume in each cross section.