基于准维多区模型的DME发动机燃烧数值模拟

提出了一种基于准维多区模型的直喷式二甲醚发动机燃烧过程的数值模拟方法，其中喷雾模拟考虑了燃油分布、液滴蒸发和空气卷吸对喷雾混合的影响。自燃着火过程的模拟以二甲醚着火反应机理为基础，建立了计及温度、压力和燃空当量比因索的着火滞燃期数据库，通过将该数据库与准维多区喷雾混合模型相耦合，对二甲醚发动机的性能和一氧化氮排放进行了预测分析．实验结果表明，模拟计算结果与实测数据符合较好．

Numerical modelling of DME engine combustion with a quasi-dimensional multi-zone model

A new quasi-dimensional multi-zone combustion model, which considers the fuel distribution,droplet evaporation,air entrainment,ignition delay and other important factors influence the performance and emission of engine,is developed to simulate the working process of dimethyl ether(DME) engines;An auto-ignition model based on the multi-step DME/air chemical kinetic mechanism was developed and an ignition delay library was generated using the computational results of DME ignition delay correlated against temperature,pressure and fuel/air equivalence ration,and the ignition delay library was coupled with the combustion model.In addition,a new way of calculating the pressure in the combustion chamber was given.The calculated results agree with that of experiments well.The model successfully simulates the combustion process under various conditions of DME engine.