Ignition of cyclopropane in shock waves

Abstract

The values of the ignition delay time of cyclopropane–oxygen–argon (cyclo-C₃H₆–O₂–Ar) mixtures of different compositions (φ = 0.333, 1, and 3) behind reflected shock waves at temperatures of 1200–1640 K and a pressure of (0.55 ± 0.05) MPa are measured. A kinetic mechanism of cyclopropane ignition using the known rate constants for the most important elementary reactions is developed. The mechanism closely describes both our own and published experimental data on the delay time of ignition of cyclopropane in shock waves over wide ranges of temperature (1200–2100 K), pressure (0.1–0.55 MPa), cyclopropane concentrations (0.05–11 vol %), and oxygen concentrations (0.25–21 vol %). It is shown that, with increasing fraction of diluent gas in the mixture, the dependence of the ignition delay time on the fuel-to-oxidizer equivalence ratio changes.