Engine hot spots: Modes of auto-ignition and reaction propagation

Many direct numerical simulations of spherical hot spot auto-ignitions, with different fuels, have identified different auto-ignitive regimes. These range from benign auto-ignition, with pressure waves of small amplitude, to super-knock with the generation of damaging over-pressures. Results of such simulations are generalised diagrammatically, by plotting boundary values of ξ, the ratio of acoustic to auto-ignition velocity, against ɛ. This...