【摘要】 研究了燃烧室几何形状对直喷式柴油机缸内气体流动和性能的影响 .用多维模型计算了三种不同几何形状的燃烧室内气体流动状况 ,系统分析了燃烧室内紊流、挤流以及湍流动能随时间和空间的分布 ,优化了燃烧室几何形状并在一台单缸柴油机上对优化的燃烧室进行了试验研究 .结果表明 ,优化后的燃烧室内气体运动强烈 ,湍流动能在较大的空间时间范围内维持高水平 .通过适当减小供油提前角 ,采用优化后燃烧室的柴油机预混合燃烧减少 ,扩散燃烧加强 ,取得了低NOx、碳烟、CO、HC排放以及低燃油消耗率的效果更多还原

【Abstract】 This paper deals with the effect of combustion chamber shape on in-cylinder air motion and performance in a DI diesel engine. Three different type combustion chambers are selected and calculated by means of multidimensional model. The turbulence, squish and turbulence energy in cylinder are systemically analyzed. Based on the numerical analysis, the experimental study is made on a single cylinder DI diesel engine. The results show that by optimizing the combustion chamber shape, the duration of high turbulence in cylinder is prolonged and the diffuse combustion during the later period of combustion process is enhanced. Therefore a good trade-off of NOx, smoke and fuel consumption is achieved by retardation of fuel injection.更多还原