Abstract
One of the sources of unburned hydrocarbon discharged from the spark ignition engine is the fuel-air mixture confined in the piston ring crevice. In this paper, the process which the fuel-air mixture confined in the piston ring crevice blows out into the cylinder is treated. Calculation model composed of three elements is developed in order to clarify the phenomenon. Three elements are thermodynamic calculation in the crevice, non-steady flow jet in the cylinder and oxidation phenomenon of the fuel-air mixture in the jet. The detailed process which fuel-air mixture in the crevice oxidizes in the cylinder is quantitatively shown by the calculation results.
