A flame structure study of lean propaneoxygen flames diluted with argon

✍ Scribed by S.J. Cook; R.F. Simmons

• Publisher: Elsevier Science
• Year: 1982
• Tongue: English
• Weight: 614 KB
• Volume: 46
• Category: Article
• ISSN: 0010-2180
• DOI: 10.1016/0010-2180(82)90014-1

✦ Synopsis

Temperature and composition profiles have been obtained through a series of fiat flames containing between 1.23 and 1.38 mol% C3H s, in which the ratio [02] : [Ar] was kept constant at 15 : 85. These profiles have been analysed in terms of the continuity equations for mass, energy, and individual species to obtain the heat release and reaction rates as a function of distance through the flame, and hence information about the reactions which control the propagation of the flame.

it is concluded that the heat release in the early part of the flame is controlled by the rate of the reaction:

OH + Call 8 = H20 + Call 7.

The subsequent steps in the oxidation are discussed in the light of known rate constant data for the likely reactions and it is shown that the initial steps in the mechanism can be considered as an oxygen-induced decomposition of the propane. Chain branching is unimportant below 1000K, but above this temperature [H] and [OH] rise rapidly, reaching their maximum values in the range 1300-1400K (final flame temperatures in the range 1500-1600K). In all cases, the maximum [H] was reached at a slightly lower temperature than the maximum for [OH], and it is shown that quasi-equilibrium between H, O, and OH can only exist in the region where the radical concentrations are decaying to their equilibrium levels. The fate of the oxygen atoms produced in the branching reaction H+O2=OH+O is considered, and it is concluded that the predominant removal process is O + H20 = 2OH