光源前置消光法测量缸内碳烟瞬态生成过程

Instantaneous Soot Formation Process Measured in Cylinder by Using Forward Illumination Light Extinction Method

开发了一种全新的碳烟测量方法——光源前置消光法(FILE),并进行了台架开发和标定试验。结果表明,FILE测量碳烟仅需一个光学窗口且激光两次穿过碳烟生成区域,因此更适用于结构位置紧凑的发动机缸内测量。采用高速摄像机拍摄了柴油燃烧过程中碳烟情况。表明:碳烟高密度区主要集中在油束下游火焰中心区和缸壁附近低氧区域;环境温度为800 K时,整个燃烧过程中碳烟瞬时质量稳定保持在100μg左右;环境温度1 200 K时,瞬时碳烟质量峰值升高一倍。

A new soot measurement method-Forward Illumination Light Extinction （FILE） method is developed, bench development and calibration test are made. The results show that the FILE method only needs one optical window to measure soot, and laser can penetrate soot formation area twice, therefore it is more suitable to be used in in-cylinder measurement for compactly structured engine. High-speed camera is used to shoot sort formation during diesel combustion, which indicates that high soot density area mainly concentrates in the downstream of fuel spray at the flame center and lowoxygen area close to cylinder wall; if the environment temperature is 800 K, instantaneous mass of soot in the whole combustion process is approx. 100 ug; if temperature rises to 1 200 K, the instantaneous mass of soot will double.