Laminar burning velocity measurements of C1-C4 alkane-air mixtures at elevated mixture temperatures

This study presents, the measurements of the laminar burning velocity (LBV) for C1-C4 alkane fuels with air at higher mixture temperatures, using an externally heated diverging channel (EHDC) method. The experimental results are shown for mixture conditions ranging from & phi; = 0.7 to 1.3, with a mixture temperature of 350-660 K at ambient pressure conditions. The temperature exponent (& alpha;) is obtained using the power-law correlation to explain the influence of LBV variation with the mixture temperature at different mixture equivalence ratios, & phi;. The maximum value of mixture burning velocity is recorded for marginally rich mixture conditions, (& phi; = 1.1) at different temperatures. The lowest value of temperature exponent (& alpha;) is observed at & phi; = 1.1. The data obtained from the current measurements are then compared with the literature results, and mechanism predictions are made using the kinetic models of USC Mech II, FFCM-1, Aramco Mech 2.0, Qin Mech, San Diego Mech, GRI Mech 3.0, and LLNL. The normalized sensitivity analysis for these straight chain C1-C4 alkane fuels reveals that the decomposition of formyl radical in reaction R163: HCO + M 4+ H + CO + M, which exhibits further major root of H atom, leading to enhancement of the LBV of these fuels at elevated mixture temperature conditions.

Automated summary

This study measures the laminar burning velocity for C1-C4 alkane fuels with air at higher mixture temperatures using an externally heated diverging channel method. The temperature exponent is obtained to explain the influence of burning velocity variation with mixture temperature at different mixture equivalence ratios. The results indicate that the decomposition of formyl radical plays a major role in enhancing the burning velocity of these fuels at elevated mixture temperatures.