Hydrocarbon Burning Velocities Predicted by Thermal Versus Diffusional Mechanisms¹

Comparison and Validation of Detailed Kinetic Models for the Oxidation of Light Alkenes

“…Apparent inconsistencies in experimental results can be attributed to the differences in S U determination methods and tools. Indeed, it is worth noting how the LLNL curve approaches to the results obtained by premixed spherical bomb by Fenard et al and premixed counter-flow configuration and linear extrapolation for the unstretched flame by Davis and Law for all the studied mixture, whereas SAM and USC predict well the nonlinear extrapolated data by the nonpremixed counter-flow twin flame configuration reported by Zhao et al Additional data for the maximum laminar burning velocity, calculated at equivalence ratio equal to 1.1, were considered as reported by Walker et al and NFPA . Eventually, an overall evaluation of the quality of fitness is not consistent for this substance.…”

“…In this work, the heat flux method results obtained by Lund University (Lund), CNRS-Nancy, Universitè de Lorraine (LRPG), and Vrije Universiteit Brussel (VUG) and the data obtained by using counter-flow flames and spherical propagating flames have been considered. For 1-butene, several authors have reported S U data by using counter-flow flame and spherical bomb. − …”

Using CHETAH to estimate lower flammable limit, minimum ignition energy, and other flammability parameters

“…Of these, thermal diffusivity is weakly dependent on the type of fuel unless the optimum concentration is high, as with ethylene and acetylene. The burning velocities of most CH and CHO fuels increase in a similar exponential fashion with increased flame temperature although it's long been known that ethylene's burning velocity is unexpectedly high relative to its flame temperature . NFPA 68 lists ethylene's burning velocity as 80 cm/s whereas the most commonly reported value is 68 cm/s.…”

Oxidation

“…The maximum burning velocities for 36 hydrocarbon-air mixtures as predicated by the semiempirical thermal equation of Semenov have been compared with National Advisory Committee for Aeronautics experimental velocities and wflth those predicted by the semiempirical Tanford and Pease diffusional equation (185) . In general, it was found that the diffusional equation predicts the burning velocity of the room temperature mixtures more closely than does the thermal equation.…”

“…Sengupta and Palit (443) compared induction times and reaction rates at different temperatures for persulfate and peroxide catalysts. Cooper (184, 185) studied the effect of peroxide structures on the rate of the initiation reaction. The following peroxide catalysts were proposed:…”