点火时刻对缸内直喷汽油机燃烧过程影响的研究

Research on Effects of Ignition Timing on Combustion for GDI Engine

利用计算流体力学(CFD)仿真技术,建立了某分层稀薄燃烧缸内直喷汽油机(GDI)的计算模型。研究了点火时刻对该GDI发动机缸内燃烧过程影响的变化规律。结果表明,随着点火推迟,缸内最高燃烧压力降低,缸内温度先升高后降低,CO的排放逐渐降低;而随着点火时刻提前,最大放热率峰值先增加后减小。

A computational model of a stratified charge and lean combustion GDI engine is established,and the rule of effect of ignition timing on the combustion process in the GDI engine is studied.The study results indicate that,as the ignition timing delays,the maximum in-cylinder combustion pressure is reduced,and the maximum in-cylinder temperature increases and then decreases,but CO emission decreases gradually.And as advance of the ignition timing,the maximum heat dissipation rate peak increases firstly and then decreases.