QUANTITATIVE DUAL-TRACER PLANAR LASER-INDUCED FLUORESCENCE MEASUREMENTS OF MOLECULAR MIXING

Simultaneous, planar laser-induced fluorescence (LIF) images of nitric oxide (NO) and acetone have been used to calculate instantaneous quan titative maps of molecularly mixed jet-fluid fraction in an axisymmetr ic shear layer. In this experiment, NO is seeded into high-purity nitr ogen jet fluid and acetone is seeded into air coflow. On mixing at the molecular level, the NO LIF is strongly quenched by oxygen from the c oflow, while the acetone signal is unaffected by the mixing process. T he extent to which the jet fluid is mixed at the molecular level is de termined on a pixel-by-pixel basis from the simultaneous NO and aceton e planar LIF images. Jets at Reynolds numbers ranging from 1000 to 50 000 are investigated. (C) 1997 Optical Society of America.