喷油规律曲线形状对柴油机燃烧过程影响的仿真分析

基于多维数值模拟的方法，研究了4种典型的喷油规律曲线形状对直喷式高强化柴油机燃烧过程的影响规律，通过分析滞燃期、放热率形状、预混燃烧及扩散燃烧放热量分配比例、燃烧重心等，得到结论：矩形喷油规律的滞燃期最短，最先着火，斜坡形喷油规律的滞燃期相对最长；矩形和梯形喷油规律对应的预混燃烧阶段放热量占得比例较大，燃烧重心更接近于上止点(TDC)，燃烧的等容度高，循环热效率高，斜坡形和楔形喷油规律预混燃烧阶段放热量占得比例较小。

Numerical Simulation and Analysis of the Influence of Fuel Injection Rate-shape on Diesel Engine Combustion Process

The influence of four typical injection rate-shapes on direct injection highly-intensified diesel engine combustion process is studied by using three-dimensional CFD software.Through the analysis of ignition delay,heat release rate shape,ratio of premixed combustion and diffusion combustion heat release,the gravity of the combustion process,it shows that: the ignition delay of rectangular injection rate is the shortest,and it gets fired first.The ignition delay of slope-shaped injection rate is the longest.Heat release accounts of the premixed combustion stage of rectangular and trapezoidal injection rate have a larger proportion,and the gravity of combustion process is closer to the top dead center(TDC),combustion capacity is higher,thermal efficiency is higher.Heat release accounts of slope and wedge-shaped premixed combustion stage takes relatively small proportion.