Low-temperature autoignition of binary mixtures of methane with alkanes С$_3$–С$_5$

The influence of alkanes С$_3$–С$_5$ on the ignition of their binary mixtures with methane in air at a temperature 523–1000 K and a pressure of 1 atm is studied. It is shown that the presence of only 1% alkanes С$_3$–С$_5$ considerably reduces the ignition delay of methane. At a concentration of 10–20%, the ignition delay practically corresponds to the autoignition delay of the added alkane. The effect of additives of heavy alkanes becomes less noticeable with increasing initial temperature. These results can be used to estimate the permissible content of the C$_{5+}$ heavy species in the gas turbine engine fuel at which their influence on the fuel knock resistance is sufficiently low. It is only 0.5%.