火花点火发动机的末端气体自燃及爆震的研究

本文介绍了火花点火发动机的末端气体自燃和爆震研究的结果。作者采用高速摄影方法，通过经改装的二冲程发动机气缸盖上的观察窗，拍摄了燃烧室内末端气体自燃和火焰传播，同时测取了气缸内三个不同位置处的压力曲线。实验结果表明，火花点火发动机的爆震是由末端气体自燃引起的。自燃一般是多点同时发生的，并在极短时间内使末燃混合气体全部燃烧。自燃通常会，但并不总是引起爆震。爆震是以缸内压力振荡的出现、碳烟的形成和爆震发生后产生气体的高速运动为特征的。

A STUDY ON END GAS AUTOIGNITION AND KNOCK IN THE SPARK IGNITION ENGINES

This paper reports the results of a study on end gas autoignition and knock in thespark ignition engines. A two stroke engine was modified to give complete overhead opticalaccess to the disc-shaped combustion chamber by the authers. End gas autoignition andflame propagation events were recorded using high speed photography. Cylinder pressurewas synchronously recorded at three positions around the cylinder head.The experimental results show that knock is caused by end gas autoignition. Autoigni-tion generally developed from multiple centres at the same time, and then the flame instantlyengUlfed the whole of the end gas region. Autoignition was usually, but not invariably fol-lowed by knock. The knock was characterized by pressure oscillations, carbon formation andhigh velocity post-knock gas motions.