Temperature measurement via oh spectrum in a flat C3H8/O2 flame by degenerate four-wave mixing

The degenerate four-wave mixing (DFWM) spectra method was employed to measure the temperature in a premixed propane-oxygen flame via OH radicals. The focus was to study the dependencies of the signal-to-noise ratio and linewidth of DFWM on the crossing angle. It was found that temperature measurements via DFWM could be made with crossing angles up to 13 °. Also, the DFWM signals were detectable for a crossing angle up to 25 ° with acceptable signal-to-noise ratio. The results suggest that it is possible to use DFWM two-dimensional imaging as a realistic diagnostic technique.