中文摘要：

将发动机多维CFD程序KIVA-3V与化学动力学程序CHEMKINIII相耦合,对正庚烷HCCI燃烧下芳香烃（苯）与多环芳烃（萘、菲及芘）的生成及演变规律进行了详细分析。发动机以正庚烷为燃料,其化学反应采用了正庚烷的燃烧与分解、多环芳烃生成的详细反应机理。结果表明在缸内混合气着火前,A1（苯）的质量浓度场较不均匀,在缸中心区域A1质量浓度较高,而在边界层及缝隙区则相对较低;然而在缸中心区域及缝隙区,A2（萘）、A3（菲）与A4（芘）的质量浓度场较低,而在边界层区则相对较高。在缸内混合气着火后,在缸中心区域及边界层区,A1-A4质量浓度较低,而在缝隙区则相对较高。混合气着火后短暂时间内为A1-A4生成的高峰期,在经历高峰期后A1-A4质量平均浓度迅速降低。同时,在排气门打开（120°CA ATDC）时,在这4种芳香烃与多环芳烃中,苯的排放量最高,萘其次,而芘的排放量则最低。

英文摘要：

By coupling the KIVA-3V engine CFD package with the CHEMKIN III chemical kinetics package,the formation and evolvement mechanisms of the aromatic（benzene） and polycyclic aromatic hydrocarbons（including naphthalene,phenanthrene and pyrene）in n-heptane HCCI combustion were simulated.N-heptane was used as fuel and the detailed reaction mechanisms of combustion of n-heptane and formation of the polycyclic aromatic hydrocarbons were adopted.The results show that the mass fraction field of A1（benzene） is very inhomogeneous and comparing with the boundary zone and the crevice zone,the mass fraction of A1 in the core zone is higher before ignition.However,comparing with the core zone and the crevice zone,the mass fractions of A2（naphthalene）,A3（phenanthrene） and A4（pyrene） in the boundary zone are higher.After ignition,comparing with the core zone and the boundary zone,the mass fractions of A1-A4 in the crevice zone are higher.Furthermore,the short time after ignition is the fastigium of the formation of A1-A4.After that time,the mass fractions of A1-A4 are decreasing rapidly.At the same time,among these four aromatic and polycyclic aromatic hydrocarbons,the mass fraction of A1 is the highest,A2 is following,and A4 is the lowest.