The use of molecular spectra simulation for diagnostics of reactive flows

Abstract

The C 2 * radical is used as a system probe tool to the reactive flow diagnostic, and it was chosen due to its large occurrence in plasma and combustion in aeronautics and aerospace applications. The rotational temperatures of C 2 * species were determined by the comparison between experimental and theoretical data. The simulation code was developed by the authors, using C++ language and the object oriented paradigm, and it includes a set of new tools that increase the efficacy of the C 2 * probe to determine the rotational temperature of the system. A brute force approach for the determination of spectral parameters was adopted in this version of the computer code. The statistical parameter c 2 was used as an objective criterion to determine the better match of experimental and synthesized spectra. The results showed that the program works even with low-quality experimental data, typically collected from in situ airborne compact apparatus. The technique was applied to flames of a Bunsen burner, and the rotational temperature of ca. 2100 K was calculated.

Research on flame temperature measurement method based on water vapor emission spectrum

“…In 1950, however, Gaydon found a difference with respect to the thermodynamic temperature when using the spectrum of OH * to measure the temperature of a hydrocarbon flame [22]. Additionally, in 2011, Passaro et al observed the high rotation temperature phenomenon when measuring the combustion temperature of liquefied gas based on the C 2 * emission spectrum [23]. The main reason for the observed differences in these cases is that the number distribution of the excited state particles has not reached its equilibrium state, and the rotational energy level is thus over-distributed.…”