Laminar Burning Velocity of Propane/CO₂/N₂–Air Mixtures at Elevated Temperatures

Abstract

The laminar burning velocity of pure and diluted high-temperature propane−air mixtures is extracted from the planar flames stabilized in the preheated mesoscale diverging channel. The experiments were carried out for a range of equivalence ratios of 0.7 ≤ Φ ≤ 1.3 and mixture temperatures of 370−650 K. The effect of dilution using CO 2 and N 2 gases (up to 40%) on C 3 H 8 −air burning velocity is also studied. Experiments complimented with computational studies of experimental conditions confirm that the stabilized flames were planar in both transverse and depth directions, and the burning velocity with heat flux in the present case is nearly equal to the adiabatic burning velocity. The detailed uncertainty analysis shows the accuracy of the present measurement within ±5%. Computational predictions of burning velocity and detailed flame structure were performed using PREMIX code. The present experiments are successfully validated against existing experimental and computational results. The peak burning velocity was observed for slightly rich mixtures even at higher mixture temperatures. The minimum value of the temperature exponent is observed for slightly rich mixtures. The burning velocity was observed to decrease with the dilution of inert gases. The addition of CO 2 shows a pronounced decrease in the burning velocity, as compared to N 2 .

Laminar Flame Velocity and Temperature Exponent of Diluted DME-Air Mixture

“…1. A mesoscale channel with a 10° divergent angle, and inlet dimension of 25 mm × 2 mm is used as referred by [7]. The channel is made up of fused quartz.…”

“…These flames were planar in both crosswise and depth direction of the channel. Other details of the setup and method can be found in [7]. …”

“…Symbols with continuous lines show the experimental data (power law fits) while dashed lines show the computational data obtained using Zhao et al mechanism [10]. Experimental data are associated with their respective uncertainty calculated as per the method reported in [7] for this experimental method. The continuous line shows the power law correlation fitted on the measured experimental data to obtain the values of temperature exponent α and reference flame velocity at temperature .…”

“…A preheated mesoscale diverging channel method validated by Akram et al [7] was used for measurements.…”

An experimental study of methane–oxygen–carbon dioxide premixed flame dynamics in non-adiabatic cylinderical meso-scale reactors with the backward facing step

“…For instance, on-line or semi-online application of such micro reactors as micro tasters in combustion systems (e.g., internal combustion engines) can upgrade the conventional combustion systems to the intelligent systems. In this regard, several efforts have been made by Maruta and co-workers [1][2][3][4][5][6][7][8], Liu et al [9], and Kumar and coworkers [10][11][12] research teams. They showed that micro and meso-scale reactors can be efficient devices which can somehow evaluate the burning characteristics of various fuel-air mixtures.…”