This study investigates the formation and evolution of soot and NO X in a high-pressure constant-volume combustion chamber. This work focuses on the effect of multiphase thermal radiation and O2 dilution in ambient/exhaust gases, sometimes also referred to as exhaust gas recirculation (EGR), qualitatively and quantitatively. The spray-A case (n-dodecane as fuel) from Engine Combustion Network (ECN) is used as the target condition. Two different soot modelling approaches have been considered: a semi-empirical two-equation model and a detailed method of moments with interpolative closure (MOMIC) model. A multiphase photon Monte Carlo (PMC) solver with line-by-line (LBL) spectral data is used to resolve radiative heat transfer. Results show that the effect of radiation on soot is minimal in spray-A. Inclusion of radiation modelling, on the other hand, marginally reduces NO prediction. Both peak soot and NO formation increase with O2 content in the ambient gas. Oxygen content in ambient gas is also found to have significant effect on soot sizes as the mean soot diameter increases along with considerable widening of the diameter distribution with the increase of O2 percentage in the ambient gas.

中文翻译：

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环境混合物中 O2 浓度和多相辐射对 ECN 喷雾 A 中污染物形成的影响

本研究调查了高压定容燃烧室中烟尘和 NOx 的形成和演化。这项工作的重点是环境/废气中多相热辐射和 O2 稀释的影响，有时也称为废气再循环 (EGR)，定性和定量。来自发动机燃烧网络 (ECN) 的喷雾 A 情况（正十二烷作为燃料）用作目标条件。已经考虑了两种不同的烟尘建模方法：半经验二方程模型和带插值闭合 (MOMIC) 模型的详细矩方法。具有逐行 (LBL) 光谱数据的多相光子蒙特卡罗 (PMC) 求解器用于解析辐射传热。结果表明，在喷雾-A 中，辐射对烟尘的影响最小。另一方面，包括辐射建模，略微降低 NO 预测。随着环境气体中 O2 含量的增加，烟尘峰值和 NO 生成量均增加。还发现环境气体中的氧含量对烟尘尺寸有显着影响，因为平均烟尘直径随着环境气体中 O2 百分比的增加而增加，直径分布显着扩大。