Modeling the Effect of Primary Atomization on Diesel Engine Emissions
Modeling the Effect of Primary Atomization on Diesel Engine Emissions
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DOI：
10.4271/2003-01-1041
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发表时间：
2003-03
期刊：
影响因子：
--
通讯作者：
Y. Yi;R. Reitz
中科院分区：
文献类型：
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作者：
Y. Yi;R. Reitz
建立了一种新的柴油喷雾雾化一次破碎模型。采用离散拉格朗日粒子法对连续液体燃料射流进行了数值模拟，并采用一种新的一维欧拉方法计算了射流的初始破碎，给出了射流破碎时间和液滴尺寸分布。一组破碎特性的相关性，包括破碎时间和液滴大小，开发了一系列的操作条件。然后，在KIVA代码中使用的相关性来预测射流的初始破碎。对于液滴二次破碎，采用Kelvin-Helmholtz/Rayleigh-Taylor混合模型。新的初级破碎模型首先通过与实验破碎长度和射流液体尖端穿透长度的比较来验证。新的破碎模型的预测进行了比较，与实验数据和预测的标准破碎模型。改进了标准模型，并与实验数据取得了良好的一致性。将新的破碎模型与其它子模型相结合应用于柴油机燃烧和排放预测。缸内压力和温度，以及排放量，进行了比较与现有的实验数据和预测，从新的和标准的崩溃模型。新的破碎模型提供了准确的预测，并表明主射流雾化过程对柴油机微粒排放有显着的影响。
A new primary breakup model was developed and applied to simulate the diesel fuel spray and atomization process. The continuous liquid fuel jet was simulated by a discrete Lagrangian particle method, and the primary breakup of the jet was calculated using a new 1-D Eulerian method that provides the jet breakup time and drop size distribution. A set of correlations of the breakup characteristics, including the breakup time and drop size, were developed for a range of operating conditions. The correlations were then used in the KIVA code to predict the jet primary breakup. For drop secondary breakups, the Kelvin-Helmholtz/Rayleigh-Taylor hybrid model was employed. The new primary breakup model was first validated by comparison to experimental breakup length and jet liquid tip penetration lengths. Predictions of the new breakup model were also compared with experimental data and predictions of the standard breakup model. Improvements over the standard model were seen, and good agreements with the experimental data were obtained. The new breakup model was applied to diesel combustion and emissions predictions in combination with other sub-models. The in-cylinder pressure and temperature, as well as emissions, were compared with available experimental data and predictions from the new and standard breakup models. The new breakup model provided accurate predictions, and shows that the primary jet atomization process has a significant influence on diesel particulate emissions.