Abstract

Laser-based imaging techniques are frequently used to assess concentration and temperature information from reactive flow systems without perturbing the system under study. Planar laser-induced fluorescence has been used to assess local temperatures with high temporal and spatial resolution. Both, single-line [1,2] and two-line [3] excitation techniques have been used. With single line techniques measured fluorescence signals are a function of temperature which includes temperature-dependent local number densities and fluorescence cross-sections. However, local concentrations of the fluorescing or scattering species under investigation have to be known. Therefore this approach is prohibitive in systems where fluctuations in gas concentrations occur and where the tracer concentration is affected by chemical processes. Two-line techniques circumvent this problem by inferring temperature information from the ratio of two individual measurements.

© 2000 Optical Society of America