음영사진의 화상해석에 의한 디젤화염에 관한 연구

A Study on the Diesel Flame by Means of Image Analysis ofn Shadow Photographs

본 연구에서는 급속압축장치에서 실현된 단발분무하염내의 매연을 레이저음영 사진법에 의하여 가시화하고, 화염내의 매연농도의 시간적, 공간적분포를 조사한다. 또 전보에서 측정된 비증발분무내의 당량비분포와 비교검토하여 디젤화염내의 매연 생 성기구를 고찰하고, 분위기조건에 따른 착화지연이 매연생성에 미치는 영향 및 매연생 성과 열발생율과의 관계를 밝힌다.

The formation and oxidation processes of soot particles in a diesel flame were investigated with a rapid compression machine. A cloud of soot particles was successfully visualized by means of the instantaneous laser shadow photographs technique and the equivalence ratio of the soot formation zone was estimated from a measured fuel concentration distribution in a nonevaporating spray. The temporal and spatial variation of soot concentration in the flame was also correlated with the rate of heat release. Soot particles appears first in a region near the flame tip when diffusion combustion period starts, and its concentration is a maximum at about the end of injection, then decreases due to oxidation. The reason for soot being formed in a fuel lean region near the flame tip is the evaporated fuel requires time to be pyrolized as it travels through the burning fuel rich zone towards the flame tip.