Water Injection in Spark-Ignition Engines, FVV Autumn Conference 2018

The oxidation chemistry in the unburned zone is modelled using the Ethanol Toluene Reference Fuel (ETRF) reactions scheme by Seidel [1] that allows for a flexible surrogate definition. This scheme was developed taking the core model from Seidel et al. [3], and reduced following the methodology in [3]. Netzer et al. [4, 5] showed that the prediction of auto-ignition in the unburned zone and laminar flame speed using this ETRF reaction scheme are sensitive to the research / motored octane number (RON/MON) rating of the surrogate and to the spark ignition timing. For the analysis in this work, a surrogate that represents a typical European gasoline fuel with a RON/MON of 94.5/88.8 is chosen. The surrogate is composed of 49.5% iso-octane, 12.7% n-heptane and 37.8% toluene by mass. Even though the reaction scheme can treat an ETRF surrogate, a TRF surrogate is chosen to reduce the number of influencing factors in the present study.