电喷柴油机优化燃烧和排放的数值模拟

应用三维CFD模拟软件FIRE,对1台6106柴油机在不同预喷油量,主预喷定时和主预喷间隔的条件下的喷雾与燃烧过程进行了数值模拟。通过分析缸内压力和温度变化以及燃烧产物的质量分数,研究了预喷射参数对燃烧过程及NOx和碳烟的影响。结果表明：采用不同预喷射策略,可有效降低缸内燃烧压力,优化柴油机的排放。随着预喷油量的增加,NOx变化不大,烟度（Soot）逐渐增加;随着预喷定时的提前,Soot生成量变化不大,NOx排放逐渐增加。

Simulation Research on Combustion and Exhaust Emission of a Diesel Engine with Electrical Control System

The Fire software developed by AVL is adopted to simulate spray and combustion process of a 6106 DI diesel engine.With numerical simulation of the different pilot injection timing,quantity and main injection timing,the changes of in-cylinder pressure and temperature and emission distribution are gotten.By analysis the data,the effect of pilot injection is studied.The results indicate that the pilot injection can improve the emission performance for diesel engines.When increasing the pilot injection quantity,the emission of NOx don＇t change obviously,but the soot is increasing;and when bring forward the pilot injection timing,the emission of soot don＇t change obviously,but the NOx is increasing.