Ignition Delay Time Measurements Of Synthesis Gas Mixtures At Engine Pressures

Shock-tube experiments were performed for synthesis gas mixtures at engine pressures, a region where not much data are currently available. Ignition delay times were obtained for four mixtures, two consisting of mostly CO/H2 and two of H2 only, for temperatures ranging from 937-1290 K and pressures up to 34.0 atm. Ignition delay times were determined using pressure at an endwall location, with emission from the hydroxyl radical A2Σ+ → X2Π transition near 307 nm used for further interpretation of results. Two state-of-the-art chemical kinetics models were compared to the experimental data. The models were in good agreement with the data above 1100 K for all mixtures, however at lower temperatures the models greatly over predicted ignition times, in some cases more than one order of magnitude. This disagreement was evident for the syngas mixtures for both fuel/air equivalence ratios studied, 0.4 and 0.7, however the disagreement was especially evident at the higher equivalence ratio