火花点火发动机爆震燃烧的实验研究

An Experimental Investigation of Knock in a Spark Ignition Engine

本文介绍了采用高速摄影法对火花点火发动机爆震进行的实验研究,总结了各种因素对爆震的影响。实验结果表明,末端气体自燃点通常是多个同时发生,分布在末端气体的不同部位;自燃通常会但并不总是会导致爆震。爆震强度并不都取决于自燃时未燃混合气量的多少,而与自燃发生时末端气体的热力状态有关,自燃出现与爆震发生之间的时间间隔愈短,则爆震愈强;当爆震发生在上止点之后时,其随自燃发生的时刻接近上止点而增强。

This paper reports an experimental investigation of knock in a spark ignition engine by using high speed natural light photography and summarizes the effects of the various faetors on knock. The experimental results show that end gas autoignition generally developed from multiple centres which were well distributed in the region of unburned mixture. Autoignition was usually, but not invariably, followed by knock. The knoek intensity was relatively independent of the mass fraetion unburned at the onset of autoignition, but more sensitive to the thermal condition of end gas. The knock intensity increase with the reduction of the time interval between the first end gas autoignition and knock appeared. When the knoek occurred after TDC, its severity increased as the onset of autoignition appeared near the TDC.