Technical Paper
Analysis of spray to spray interaction and smoke emission for diesel multiple injections and quick rising injection rate
2019-12-19
2019-01-2272
Diesel engines have smoke trade-offs with both NOx and combustion noise. Both the increment of air entrainment into the spray and deceleration of heat release rate slope which become quickly thanks to the increase of air entrainment are effective for overcoming the trade-off between smoke emission and combustion noise. In this study, effect of quick rising injection rate and pre-injection was focused as an enabler for the both. The mechanism of improvement in the trade-off caused by the quick rising injection rate and pre-injection was clarified by analyzing characteristics of spray and combustion, interaction of pre-injected spray to main-injected spray and behavior of smoke emission. Some visualization techniques were adapted to analysis of sprays and combustions. Spray momentum measurement was used for the air entrainment and mixture formation process analyzation.