Self-ignition and combustion stability in a methanol fueled low heat rejection ceramic ATAC engine - Analysis of cyclic variation at high wall temperatures and lean burn operation

ATAC (Active Thermo-Atmosphere Combustion) is stable at its lean limit because it is bulk-like and non-propagating in nature and is initiated by self-ignition. A low heat rejection methanol-fueled engine was used to investigate the influence of making the fuel-air ratio leaner and increasing the combustion chamber wall temperature on cyclic variation of ATAC ignition and combustion. The cyclic variation of self-ignition timing, combustion duration, total heat release, and instantaneous wall heat flux was analyzed, from which correlations between self-ignition timing and combustion duration, self-ignition timing and total heat release, and combustion duration and total heat release were obtained.