An Improved Empirical Model for Describing Auto-ignition

This paper develops an improved empirical autoignition model that includes the cool-flame phenomenon. It is calibrated for primary reference fuel (PRF) blends from 0 to 100 octane and also blends of methanol with 80 PRF. Methanol does not exhibit a cool-flame and hence the blends provide insight regarding the probable blending profile of multi-component gasolines and future synthetic fuels. The model was calibrated using ∼1500 detailed chemical kinetic simulations mapping a wide pressure, temperature and air-fuel ratio domain. Besides being a computationally elegant autoignition predictor for engine simulations, the model also provides a technically defensible structure for encapsulating experimental data from autoignition research devices such as rapid-compression machines.