SUPERSONIC COMBUSTION IN PREMIXED HYDROCARBON-AIR FLOW.
GENERAL APPLIED SCIENCE LABS INC WESTBURY N Y
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A study of the mechanisms of ignition and flame propagation of supersonic air-hydrogen fuel mixtures at temperatures below the published autoignition limits was made. The hydrocarbons considered were methane CH4, ethane C2H6, ethylene C2H4 and propane C3H8 with flame ignition and stabilization by means of a small hydrogen-oxygen pilot flame. Flame speeds for methane, ethane, and ethylene-air mixtures were found to be four, three and two times smaller, respectively than hydrogen-air flame speeds under similar flow conditions. The dependence of the flame speed on the initial mixture temperature was correlated by a simple exponential relation. Addition of a small amount of hydrogen to a methane-air mixture resulted in doubling the observed flame angle. Finally, measurements of flame temperature distribution and spreading rate were shown to be in agreement with results of a theoretical analysis incorporating finite rate methane-air chemistry and axisymmetric diffusive flow. Author
- Combustion and Ignition