Effect of equivalence ratio distribution on end-gas autoignition and pressure wave generation process
Knocking simulation in a constant volume reactor was carried out by using the compressible Navier-Stoke equations with a detailed reaction mechanism of n-heptane. In this study, we investigated the influence of equivalence ratio distributions on knocking combustion, assuming multistage injections in an engine cylinder. The result showed, in a condition (Case B in the lower left figure), characteristic two-stage autoignition occurred (lower right figure), leading to the increase of knocking intensity. The study demonstrated the importance of fuel distributions in the knocking phenomenon.
Details of contents：
Tomonari Satoh, Hiroshi Terashima, “Effects of fuel/air mixture distribution on end-gas autoignition and pressure wave generations in knocking combustion”, 26th International Colloquium on the Dynamics of Explosions and Reactive Systems (2017)
The result uniquely provided a two-staged end-gas autoignition phenomenon with a non-uniform fuel/air distribution, resulting in a larger knocking intensity. The study, thus, clearly demonstrated the importance of fuel/air distributions on knocking, while identifying the key physics behind it. Please see our paper.
Hiroshi Terashima Hokkaido University Professor