Radiation and Burning Velocity Studies of Propane-Oxygen-Nitrogen Mixtures

In several recent papers, the authors have assumed that the spectral intensity ratio of suitable emission lines (e.g., C2/CH) from laminar flames was dependent only on the equivalence ratio for a particular fuel-oxidizer system. The objective of this study was to determine the effect of various amounts of inert diluent on the spectral intensity ratio of a propane-oxygen-nitrogen system. Experiments were conducted with inert diluent contents of 50, 60, 70, and 80 percent nitrogen (by mass) and with equivalence ratios of 0.6, 0.8, 1.0, 1.2, 1.4, and 1.6. The spectral intensity ratio was found to be a function of the percentage of inert diluent aa well as a function of the equivalence ratio. Since the flame temperatures are dependent on the percentage of inert diluent, it appears likely that the spectral intensity ratio is a function of temperature. The angle method was used t:o obtain burning velocity data. The relative changes of burning velocity with change of composition were deduced from the experimental data.