燃空当量比对直喷甲醇发动机混合气浓度分布影响

基于一款经柴油机改装的非均匀分布的五喷孔的缸内直喷甲醇发动机,利用商用CFD数值计算软件计算模拟了不同燃空当量比下缸内混合气浓度分布情况。计算结果表明:经特殊改装的喷孔能够提高火花塞附近的混合气浓度,同时还改善缸内整体混合气浓度分布,使得缸内混合气浓度分布更加合理,缩小混合气浓度极度稀薄区域面积。

Based on a modified diesel engine with non-uniform distribution of five injection holes, a commercial CFD numerical calculation software was used to simulate the distribution of in-cylinder mixture concentration under different fuel/air equivalent ratios. The calculation results show that the specially modified nozzle can increase the mixture concentration near the spark plug and improve the overall mixture concentration distribution in the cylinder, which makes the mixture concentration distribution in the cylinder more reasonable and reduces the area of extreme rarefaction of mixture concentration.