Measurement of Supersonic Injection Flowfield Using Acetone PLIF

Abstract

The structure of the flowfield formed by normal sonic injection into a Mach 1.8 air stream was investigated using acetone planar laser induced fluorescence (acetone PLIF). Parametric calculation of fluorescence intensity indicates that it represents molar concentration within ±2.5% error for the present experimental conditions. For the special situation of isentropic flow without any mixing, the Mach number can be deduced from the fluorescence intensity. Mach number distribution from PLIF data agreed well with that obtained from PIV measurement. The visual images of jet trajectories obtained from acetone PLIF are compared with those obtained from Mie scattering and indicate that the acetone PLIF produces a reasonable trajectory, while Mie scattering overestimates the jet penetration.