Analysis of knocking combustion with methanol/iso-octane and ethanol/iso-octane blends in a spark-ignition engine

•Numerical simulation was carried out to simulate knock combustion of methanol/iso-octane and ethanol/iso-octane blends.•A new parameter I was come up for the description of the Intensity of interaction between flame core and pressure wave.•Dimensionless IIntegral was calculated basing on parameter I to evaluate the intensity of knock.