Influence of the stratified fuel-air charge pattern on economic and environmental indicators of a two-stroke engine with spark ignition

The results of experimental studies on load characteristics (3000 rpm) of a two-stroke engine 1D 8.7 / 8.2 with spark ignition, crankcase scavenging, air cooling, and direct fuel injection have been considered in the paper. Changing the design of the combustion chamber and spray nozzle allowed accomplishing different patterns of fuel and air charge formation. Forming lean fuel-air mixture (1.5>λcyl>1.0) is carried out at fixed composition in the clearance volume. Forming rich fuel-air mixture (1.0>λ>0.8) in the spark plug area with the air at λcyl λ>1.0) in the spark plug area with the air λcyl<5 near the clearance volume walls enables the generation of a stratified lean fuel-air charge. It has been revealed that generating the stratified lean fuel-air charge allows a reduction of fuel consumption by 16–27 % and a decrease in CO and CH emissions with exhaust gases up to 14 times in comparison with the generation of lean fuel-air charge.