Rotational Temperature Measurement of NO in a Sooting Diffusion Flame through Laser-Induced Fluorescence Spectrum

Abstract

LIF thermometry in a sooting diffusion flame was newly proposed based on a spectral matching method. A tunable ArF excimer laser was used to excite the several absorption lines in the D2Σ+←X2II (0, 1) band system of NO. In the case of sooting diffusion flame, emission spectrum consisted of NO and O2 fluorescence, and off-resonance emissions related to the soot. The O2 fluorescence and the off-resonance emissions overlapped on the NO fluorescence. However, the off-resonance emissions near the vacuum ultraviolet region (VUV) were weaker than the NO fluorescence, and thee (0, 3) band of the NO fluorescence, which appeared near the VUV region, was free from the O2 fluorescence. Therefore, NO rotational temperature in a sooting diffusion flame could be measured by the spectral matching method using the e (0, 3) band. By using this technique, NO rotational temperature in a propane diffusion flame could be measured.