大功率柴油机喷油提前角对缸内燃烧过程的影响

针对某型大功率柴油机,采用试验和计算流体力学（CFD）仿真相结合的方法,研究了大功率柴油机在不同喷油提前角下的燃烧特性,着重分析了缸内最大爆发压力、峰值角、最大压力升高率、燃烧始点等参数的变化趋势,同时对缸内速度场、燃空当量比分布和温度场的变化进行研究,得出喷油提前角的变化对预混合滞燃期的改变是影响柴油机燃烧过程的主要因素,随着喷油提前角的增大,滞燃期内可燃混合气增多,缸内最大爆发压力、最大压力升高率和缸内最高温度随之升高。

Impact of the Injection Timing on the Combustion in the Cylinder of High Power Diesel Engine

The test and CFD simulation are used to analyze the impact of the combustion feature at different injection angle of advance of the high power diesel engine.The variations of the max breakout pressure,the angle of the max pressure,the max rate of pressure rise and the beginning point of combustion are analyzed.The changes of the velocity field,the fuel and air equivalent proportion and the temperature field are studied.According to the research,it follows that the variation of the pre-mix combustion delay caused by the injection timing is the main factor to impact the combustion of diesel engine.With fuel injection timing prolonged,the combustible mixture formed at the pre-mix combustion delay is increased.The max breakout pressure,the max rate of pressure rise and the max temperature are higher.