Effect of the blending ratio of ATJ-SPK on combustion and emission characteristics of an aviation piston engine

The application of alcohol-to-jet synthetic paraffinic kerosene (ATJ-SPK) can effectively address issues such as excessive pollutant emissions from aviation kerosene during use, which is highly beneficial for alleviating global climate problems. The effect of ATJ-SPK blending ratios on the combustion and emission characteristics of a direct-injection aviation kerosene piston engine was explored in this study. The results show that as the blending ratio increases from 0 to 40%, the maximum in-cylinder average pressure and NO x formation amount gradually decrease, while CO and soot formation amounts initially decrease and then increase. Specifically, when the blending ratio increases from 0 to 20%, the maximum in-cylinder average pressure decreases by 7.5%, while NO x , CO, and soot formation amounts drop by 16.5%, 34.8%, and 48.7% respectively. When the ratio rises to 30%, CO further decreases by 52.2% (relative to 0). At 40%, the maximum in-cylinder average pressure falls rapidly by 34.2%, NO x accumulates a 69.6% reduction (relative to 0), soot formation surges, and CO increases by 76.2% (relative to 30%). Through analysis, it is found that a blending ratio of 20% can maximize emission reduction benefits while having a relatively small impact on engine power output, thereby providing a theoretical foundation.