Autoignition of propane behind shock waves

The ignition delay times of C3H8-O-2-Ar mixtures of various compositions are measured behind reflected shock waves at temperatures of 1220-1750 K and a pressure of (0.65 +/- 0.05) MPa. A kinetic mechanism of propane ignition based on the known rate constants of the key elementary reactions is developed. The scheme closely describes our own and published experimental data on the ignition of propane-oxygen mixtures behind shock waves over a wide ranges of temperatures (1100-1750 K), pressures (0.12-0.65 MPa), and propane (0.05-11%) and oxygen (0.25-21%) concentrations. At T < 1100 K, neither the proposed kinetic scheme nor the different kinetic mechanisms reported in the literature can satisfactorily describe the experimentally measured ignition delay times for propane behind shock waves. We suggested that, at T < 1100 K, the limiting process is the propagation of deflagration flames from individual C3H8 ignition hotspots. Numerical calculations of the propagation of a one-dimensional flame performed using the proposed kinetic scheme qualitatively confirm this assumption.