Simultaneous measurements of NO, OH, and the major species in turbulent flames

Abstract
We present a method for obtaining time-resolved point measurements of the pollutant nitric oxide (NO), hydroxyl (OH), the temperature, and the major species—using a combination of laser-induced fluorescence and Rayleigh/Raman scattering—in turbulent flames. Using single-shot measurements of temperature and the major species concentrations, we calculate the mixture fraction, which characterizes the state of mixing in the gas, and the corrections for the NO and OH fluorescence. For NO the time-resolved detection limit is ∼ 10 parts in 106. We demonstrate this facility with measurements of NO versus the mixture fraction in a turbulent nonpremixed H2 jet flame.