均质压燃发动机燃烧与排放的多区模型模拟

应用一个有质量交换的6区模型模拟正庚烷在HCCI发动机中的燃烧和排放特性．通过把缸内划分为缝隙区、边界层区、外核心区和内核心区，加入Woschni传热模型计入了缸内的温度和浓度的不均匀分布．全部计算基于正庚烷燃烧的包含57种组分290个反应的详细机理，结果表明，该多区模型合理地模拟了HCCI发动机的燃烧过程，并可满意地预测出HC、CO和NO的排放．最后采用此多区模型分别讨论了缝隙容积、边界层厚度和壁面温度对HCCI发动机的燃烧和排放的影响．

The Simulation of HCCI Engine with a Multi-Zone Model

A six zones model with mass exchange was developed to simulate the combustion and emission of homogeneous charge compression ignition (HCCI) with n-heptane as the fuel. The fuel and temperature inhomogeneities were brought to the calculation by dividing the chamber into a crevice zone, a boundary zone, a outer core zone and several inner core zones. The simulation was based on the n-heptane mechanism with 57 species and 290 reactions. The results show that this multi-zone model succersfully simulates the HCCI engine combustion process and can predict emissions of HC, CO and NO correctly. At last, the effects of crevice volume, boundary thickness and wall temperature on HCCI engine combustion and emissions were discussed using this multi-zone model.