Temperature dependency of the laminar burning velocity of fuel-rich methane oxygen measurements

First experiments to determine laminar burning velocities of methane-pure oxygen mixtures were carried out in 1932 by Jahn [1] for a wide range of equivalence ratios Φ (0.2 to 2.64) using a Bunsen burner. Since then, new and most important more accurate methods were developed to determine laminar burning velocities. One of these methods, namely the Heat Flux Method, which was introduced by de Goey et al. [2] in 1993, was used in the current work to validate the results for fuel-rich methane oxygen mixtures (Φ = 2.38 to 2.64) as published by Jahn. Regarding the current Heat Flux Bruner setup the range of velocities that can be determined are limited between 9 and 50 cm/s, which also limits the range of investigated equivalence ratios (Φ = 2.38 to 3.03), which is wider as the one investigated by Jahn [1]. Furthermore, the influence of the pre-heating temperature was also investigated by a variation of it from 263 up to 455 K. Based on these experimental data the temperature dependency of laminar burning velocities of fuel-rich methane oxygen mixtures was determined and as a result the coefficient α of the power law correlation SL = SL0 (T/T0)α was calculated. ... mehrDue to the increase of the laminar burning velocity at higher pre-heating temperatures, the laminar burning velocities could also be determined at equivalence ratios up to a maximum value of Φ = 3.33 (TP = 455 K). The increase in accuracy of measurement methods to determine laminar burning velocities over the last decades [3] leads to an observed decrease in measured flame speeds. This tendency is confirmed in the current experiments, where the determined laminar burning velocities are lower than the ones measured by Jahn [1]. Regarding the temperature dependency of the laminar burning velocity, the results indicate that for the range of investigated equivalence ratios and temperatures (300 K to 455 K) the power law coefficient α was observed to be almost constant.