Temperature measurement in fuel-rich non-sooting low-pressure hydrocarbon flames

Several temperature measurement techniques were compared for the investigat ion of fuel-rich, premixed, flat, low-pressure flames of propene, acetylene , and cyclopentene with maximum temperatures around 2400 K. Vibrational Sto kes/anti-Stokes Raman measurements with a KrF excimer laser using CO, H-2, and H2O as temperature indicators were examined at 50 and 200 mbar for diff erent flame stoichiometries. Also, laser-induced fluorescence (LIF) of OH i n the A-X band was used, and complementary lifetime measurements were perfo rmed to account for a variation of fluorescence quantum yield with rotation al quantum number. LIF using seeded NO (0.2%-1.0%) was applied both in poin t wise and 1D temperature measurement in spite of the anticipated interacti on of NO with the fuel-rich flame chemistry. Furthermore, thermocouple meas urements were performed in the preheat zone. These techniques were compared with respect to accuracy and the potential for routine applications under fuel-rich low-pressure conditions.