The effects of injection control parameters such as injection timing and injection pressure on combustion and spray characteristics of GDI optical engine with a centrallymounted injector were investigated. The results indicate that the combustion duration and ignition delay first decrease and then increase with the advance of third stage injection timing θSOI3. The combustion parameters both show an obvious inflection and the cycle variation coefficient of indicated mean effective pressure becomes small at 120°BTDC. The short distance between piston and top dead center in compression process led by the too late injection of third stage fuel will easily cause fuel beam to impact the piston surface. Increasing the injection pressure may shorten the combustion duration and improve the degree of constant volume combustion. However, the too large injection pressure will prolong the fuel penetration, the tendency of fuel beam to impact cylinder wall becomes more obvious, and hence the ignition delay and combustion duration extend.
DU Jiakun,CHEN Hong,LI Yuhuai,YE Lin,ZHANG Shuang.
Effects of Injection Control Parameters on Spray and Combustion of GDI Engine with CentrallyMounted Injector[J]. Vehicle Engine. 2018, 0(2): 17-22 https://doi.org/10.3969/j.issn.10012222.2018.02.003
