NUMERICAL INVESTIGATION OF IGNITION DELAY TIMES IN A PSR OF GASOLINE FUEL

This paper reports on preliminary results of a study conducted by simulating the ignition of a flammable mixture of gasoline and air, in a perfectly stirred reactor (PSR). Several ignition conditions have been analyzed by varying the initial temperature, the pressure and the equivalence ratio and temperature of the feeding mixture. The fuel has been described with a surrogate composed by a mixture of nheptane, toluene and iso-octane. The detailed chemical mechanisms proposed by the CRECK group of Politecnico di Milano, the POLIMI-TOT-NOX-1407, consisting of 484 species and 19341 reactions has been adopted to achieve a high fidelity in the reproduction of the ignition delay time. The effect of mixture composition, pressure, initial temperature and residence time is illustrated. It is shown that significant deviations from the ignition delay time (IDT) measured in batch reactor arise. The dependency shown upon the parameters space can be of great help in explaining the ignition behavior in real engines, which is often difficult to interpret.