This paper uses a Kinetic Monte Carlo model that includes processes to integrate curvature due to the formation of five- and seven-member rings to simulate polycyclic aromatic hydrocarbons (PAHs) growing in lightly sooting ethylene and acetylene counterflow diffusion flames. The model includes new processes to form seven-member rings via hydrogen-abstraction-acetylene-addition and bay closure reactions on sites containing partially embedded five-member rings. The model additionally includes bay closure and HACA bay capping reactions for the integration of five-member rings. The mass spectra of PAHs predicted by the model are assessed against experimental data, and the distribution of embedded five-member rings and seven-member rings is studied as a function of spatial location, molecule size and frequency of events sampled in the simulation. The simulations show that the formation of seven-member rings and the embedding of five-member rings is a competitive process. Both types of rings are observed more frequently as the simulation proceeds from the fuel outlet towards the stagnation plane. Approximately 15% of the events that integrate curvature resulted in the formation of a seven-member ring coupled to an embedded five-member ring, and the remaining 85% of events embedded five-member rings via the formation of six-member rings. The proportion of PAHs containing embedded five-member rings and/or seven-member rings is observed to be a function of PAH size, passing through a maximum for PAHs containing 15–20 six-member rings. However, the proportion of PAHs containing both types of ring increases with PAH size, where upwards of 10% of PAHs containing at least one five-member ring and 15 or more six-member rings also contain a seven-member ring.

本文使用动力学蒙特卡洛模型，该模型包括由于形成五元环和七元环而对曲率进行积分的过程，以模拟在轻度冒烟的乙烯和乙炔逆流扩散火焰中生长的多环芳烃（PAH）。该模型包括通过氢吸收-乙炔加成和在包含部分嵌入的五元环的位点上的海湾封闭反应形成七元环的新过程。该模型还包括托架闭合和HACA托架封盖反应，用于集成五元环。利用实验数据评估了模型预测的多环芳烃的质谱，并研究了嵌入的五元环和七元环的分布与空间位置，分子大小和事件发生频率的关系。仿真表明，七元环的形成和五元环的嵌入是一个竞争过程。随着模拟从燃料出口向停滞平面前进，会更频繁地观察到两种类型的环。积分曲率的事件中约有15％导致形成了一个与嵌入的五元环耦合的七元环，其余的事件的85％通过形成六元环而嵌入了五元环。观察到包含嵌入的五元环和/或七元环的PAHs的比例是PAH尺寸的函数，对于包含15-20个六元环的PAHs来说是最大。但是，包含两种类型环的PAH的比例随PAH尺寸的增加而增加，