Advances In Understanding Acetylene Combustion From MBMS Experiment and Modeling

Flame chemistry from acetylene combustion has been a recurring research target of flat-flame molecular-beam mass spectrometry (MBMS), especially near the sooting limit. In the long history since this research theme began, progress has advanced from empirical observation of species to modeling and precise species identification. New insights are especially made possible by modeling data from VUV-PI MBMS in our apparatus at Lawrence Berkeley National Laboratory and a sister apparatus at the National Synchrotron Radiation Laboratory in Hefei, China. Current modeling
reveals the good fundamental understanding of C2H2 chemistry and some areas where further advances are needed. In this work, we are going to present the detailed flame structure for two premixed laminar flat flames (with stoichiometries of 0.95 and 2.41) characterized from flame-sampling Photo-ionization Molecular Beam Mass Spectrometry. Temperature profiles are measured from type-R thermocouple. An updated reaction mechanism is used for flames simulation with generally good agreement to the experiment. The oxidation and molecular-weight growth chemistry of acetylene combuistion under the fuel-lean and fuel-rich conditions is investigated based on the reaction pathway and flux analyses.