Flame propagation and combustion characteristics of stratified charge propane-air mixture with swirling flow in a constant-volume vessel

The flame propagation and the combustion characteristics of stratified fuel concentration field were studied using a cylindrical constant volume vessel. A swirling fuel-air mixture was produced in the vessel. A rich fuel concentration was formed near the center of the vessel by the injection of propane and lean mixture near the wall. The gas flow field was obtained with a laser Doppler velocimeter in advance. The pressure history in the combustion chamber was analyzed to determine the combustion characteristics. The flame could propagate and the combustion occurred even in an ultra lean mixture of equivalence ratio of 0.3:1 in total. As the fuel concentration near the spark location approximates stoichiometric mixture ratio, flame propagation of the initial stage of the combustion became faster. When stratified mixtures with the same pattern of fuel concentration but different turbulence intensities were considered, the main combustion period decreased with turbulence intensity, since the burning velocity also increased. Original is an abstract.