The result. of a new experimental programme to measure auto-ignitiondelay time. in mainly lean ((/J = 0.5) propane-airmixtures at intermediate temperatures in the range 850 K upwards and pressures 5-40 bar are described. The delays are compared to predictions obtained by thc integration of two detailed chemical kinetic reaction schemes. Experimentally, a decrease in activation energy was observed at around 1000 K. The work shows that extrapolation of ignition delays obtained at high temperatures T > 1000 K can lead to significant overestimation of the actual delay times at lower temperatures. Despite the introduction of additionalkcy reaction. the kinetic schemes used could not fully reproduce the delay times observed experimentally at temperature below ca. 1000 K.
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