燃烧室形状对直喷柴油机燃烧性能影响的三维数值模拟

Three-Dimension Models of the Effects of Combustion Chamber Geometry on Combustion Characteristics in a DI Diesel Engine

为研究燃烧室形状对直喷柴油机燃烧性能的影响,应用发动机燃烧过程多维模拟软件FIRE对4类燃烧室柴油机燃烧过程进行了三维数值模拟.探讨了燃烧室几何形状影响燃烧性能的作用机理.结果显示,燃烧室几何结构对缸内的流场、喷雾以及燃烧特性都有较大影响.缩口燃烧室的缸内流场强度要强于直口燃烧室,进而导致缩口燃烧室的油气混合和燃烧性能要优于直口燃烧室.

In order to study the effects of combustion chamber geometry on combustion characteristics in a DI diesel engine, CFD software FIRE is used to simulate the combustion processes in four types of combustion chambers of the diesel engines. The effect mechanism of the combustion chamber geometry is analyzed. Results show that the combustion chamber geometry exerts considerable influence on incylinder flow field, spray and combustion performance. The intensity of flow in the re-entrant type combustion chamber is stronger than that in the Maxican-hat geometry combustion chamber. As a resuit, the fuel/air mixing and combustion performance of the re-entrant type chamber are better than that of the Maxican-hat type chamber.