Numerical study towards smoke-less and NOx-less HSDI Diesel engine combustion

This paper aims to address the above issues by considering the performance of 2.5 HSDI Common rail Diesel engine operating at characteristic point of the EUDC test emission cycle (i.e., bmep= 8 bar, engine speed= 2733 rpm). This allows to considers a medium load engine (i.e., 45%) condition much more demanding than that considered by Sasaki et al. and Kimura et al. []. The present research is based on numerical simulations performed by using the Kiva 3 code updated with physical sub-models at the University of Bologna. The methodology aims to integrate, not substitute, experiments allowing a deep analysis of the mechanisms driving low-temperature combustion. The combined influence of EGR cooling and EGR rate on combustion characteristics and emission formation is analyzed. Then, possible improvements to mixture formation are discussed with particularly emphasis on the use of multiple injection.