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本文采用改进的详细碳烟模型,耦合了由正庚烷和甲苯组成的混合燃料的简化反应机理,以一台单缸柴油机为研究对象,对此详细碳烟模型预测柴油机碳烟生成和氧化过程的准确性和有效性进行了验证。结果表明,模拟得到的缸内压力和放热率曲线,以及着火时刻和试验结果非常吻合,得到碳烟排放量的模拟值与试验值的变化趋势基本一致,因而本文的详细碳烟模型可较好地预测不同工况条件下柴油机碳烟颗粒排放的变化趋势;同时,采用本文提出的详细碳烟模型对柴油机内碳烟颗粒数浓度和平均尺寸进行数值模拟,结果表明,随着时间的增长,碳烟颗粒的数量先增加后减小,尺寸分布范围由小变宽,然后再变小,最后其分布趋于稳定。
In this paper, an improved detailed soot model is used to couple the simplified reaction mechanism of a mixed fuel consisting of n-heptane and toluene. A single-cylinder diesel engine is taken as a research object. The detailed soot model is used to predict the soot formation and oxidation process The accuracy and validity of the verification. The simulation results show that the simulated cylinder pressure and heat release rate curves, as well as the ignition time and test results are in good agreement with each other. The simulation results of the soot emission are in good agreement with the experimental values. Therefore, the detailed soot model in this paper can be compared Meanwhile, using the detailed soot model proposed in this paper to numerically simulate the particle number concentration and average size of soot particles in a diesel engine, the results show that with the increase of time , The number of soot particles first increases and then decreases, the size distribution range from small to widened, and then smaller, and finally its distribution tends to be stable.