Abstract

Picosecond time-resolved laser-induced fluorescence (PITLIF) can potentially be used to obtain measurements of minor species concentrations in rapidly fluctuating flames. Previous studies demonstrated this potential for atomic sodium by monitoring the temporal fluorescence signal with both an equivalent-time and a real-time sampling method. In this developmental study, PITLIF is used to determine hydroxyl concentrations in laminar CH₄–O₂–N₂ flames by the measurement of both the integrated fluorescence signal and the fluorescence lifetime. The quenching environment can be monitored with real-time sampling, and thus the necessary quenching rate coefficient is obtained in 348 μs, which is fast enough for use in many turbulent flows. Fluorescence lifetimes of OH are also measured at different equivalence ratios in laminar flames by the use of the equivalent-time sampling technique. These results compare favorably with predicted lifetimes based on relevant quenching cross sections and calculated species concentrations.

© 1996 Optical Society of America

Time-series measurements of CH concentration in turbulent CH₄/air flames by use of picosecond time-resolved laser-induced fluorescence

Michael W. Renfro, Michael S. Klassen, Galen B. King, and Normand M. Laurendeau
Opt. Lett. 22(3) 175-177 (1997)

Two-point time-series measurements of hydroxyl concentration in a turbulent nonpremixed flame

Jiayao Zhang, Galen B. King, Normand M. Laurendeau, and Michael W. Renfro
Appl. Opt. 46(23) 5742-5754 (2007)

Quantitative hydroxyl concentration time-series measurements in turbulent nonpremixed flames

Michael W. Renfro, Galen B. King, and Normand M. Laurendeau
Appl. Opt. 38(21) 4596-4608 (1999)

Real-time acquisition of laser-induced fluorescence decays

Thomas A. Reichardt, Michael S. Klassen, Galen B. King, and Normand M. Laurendeau
Appl. Opt. 34(6) 973-976 (1995)

Measurements of absolute CH concentrations by cavity ring-down spectroscopy and linear laser-induced fluorescence in laminar, counterflow partially premixed and nonpremixed flames at atmospheric pressure

Sameer V. Naik and Normand M. Laurendeau
Appl. Opt. 43(26) 5116-5125 (2004)