【摘要】 针对柴油发动机在不同负荷下碳烟排放特征的演变和发展，依据ECN喷雾定容燃烧实验中碳烟的测量数据，基于OpenFOAM开源软件喷雾燃烧求解器，耦合半经验现象学碳烟预测模型．通过Φ-T关系图呈现环境因素改变对碳烟形成及氧化各阶段的影响，分析各子过程的分布区域和演化规律，进而提出环境条件对碳烟生成及演化历程的影响机制．研究结果表明：现象学模型本身能够较好地反映碳烟的分布情况．碳烟生长主要发生在当量比Φ>3区域；而碳烟发生氧化的区域，也是OH主要分布的区间，大多位于当量比Φ<2的位置．环境温度和密度的增加初期促进了碳烟的成核，加剧了颗粒的聚并速率，使得颗粒数显著下降；而环境氧体积分数的增加抑制了碳烟颗粒数的增长和聚并速率，使碳烟整体尺寸趋于小尺寸、高密度的分布情况．更多还原

【Abstract】 Aimed at the soot formation and evolution under different diesel engine operation conditions,this study is carried out based on the measured data of soot generated in constant volume spray combustion by the engine combustion network(ECN). The combustion solver based on an open source CFD platform(Open FOAM)is employed and the classical phenomenological multi-step soot model is coupled in the numerical simulation. The effect of ambient conditions on each soot sub-formation and oxidation process is revealed through the Φ-T diagram,and the distribution region and evolution of soot formation process are analyzed,with the aim of proposing the influencing mechanism of initial operation conditions on soot formation and oxidation. The results show that the phenomenological soot model can well predict the distribution of soot. The surface growth region of soot is mainly located in the area with the equivalence ratio greater than 3.0. The oxidation region is mainly distributed in the area with the equivalence ratio smaller than 2.0,which is also the main distribution area of OH species. The increase in ambient temperature and density promotes both nucleation and the coagulation rate and reduces the particle number density. The increase in ambient oxygen volume fraction suppress both nucleation and the coagulation rate,thus resulting in smaller size and higher density distribution of soot particles.更多还原