An Analytical Approach to Auto-Ignition and Knock in Internal Combustion Engines

A simplified analytical approach to the problem of determining the conditions for the onset of knock in spark ignition engines is made, using a criterion for knock based on a hypothetical gross chemical reaction of the fuel-air mixture in the end gas. It is then applied to auto-ignition studies in motored engines. Parameters such as compression ratio, initial temperature and pressure, fuel properties, ignition timing, speed and mixture strength are considered. This simplified treatment may form a basis for interpolating data, particularly when few parameters are being varied at a time. Some aspects of the treatment are illustrated by experimental engine data, drawing whenever possible from already published results.