1.前言迄今,直喷式柴油机已被广泛地用作大型动力装置,由于其热效率高、废气有害排放物较少,故近年来在小型车用发动机上的应用也已日益引人注目。为了提高热效率,并进而设计排放少的发动机,就要调整影响柴油机燃烧的各项参数,并用实验方法求出这些参数的变化对发动机性能的影响,以选出其最佳值。可是,并不是每一项参数只是单独地对发动机性能有影响,所以常需将若干参数作排列组合进 1. Introduction To date, direct injection diesel engines have been widely used as large-scale power plants and have been attracting increasing attention in recent years for use in small-car engines due to their high thermal efficiency and low emission of harmful emissions. In order to improve the thermal efficiency, and then design the engine with less emissions, it is necessary to adjust the various parameters that affect the combustion of the diesel engine and experimentally determine the influence of these parameter changes on the engine performance to select the optimum value. However, not every parameter affects the engine performance alone, so it is often necessary to arrange a number of parameters