Study on flame lift-off length in diesel combustion using ECFM-3Z model

摘要

Three-dimensional simulations of ignition and combustion of a diesel spray were conducted using STAR-CD CFD codes. A recently developed combustion model (Extended Coherent Flame model 3Z -ECFM-3Z) is used for this study. The effects of ambient temperature、orifice diameter and EGR on the flame lift-off length of a diesel spray were investigated. Sandia experiments conducted in a high pressure and high temperature constant volume combustion bomb were chosen for the simulations and validations. OH is used as a marker of lift-off length and flame region. The results showed that the simulation using ECFM-3Z model are in good agreement with the experiment data and these parameters would significantly influence the flame lift-off length and affect diesel combustion and emission processes. Study on lift-off length will help us to improve the combustion process.