Spatio-temporal identification of plume dynamics by 3D computed tomography using engine combustion network spray G injector and various fuels
Spatio-temporal identification of plume dynamics by 3D computed tomography using engine combustion network spray G injector and various fuels
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DOI：
10.1016/j.fuel.2020.118359
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发表时间：
2020-11
期刊：
影响因子：
7.4
通讯作者：
Joonsik Hwang;L. Weiss;I. Karathanassis;P. Koukouvinis;L. Pickett;S. Skeen
中科院分区：
文献类型：
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作者：
Joonsik Hwang;L. Weiss;I. Karathanassis;P. Koukouvinis;L. Pickett;S. Skeen
了解燃烧室中的羽流方向和混合气质量对于提高发动机性能至关重要。虽然使用激光和X射线设备的各种诊断已被应用于识别羽流方向，但大多数应用需要复杂的实验设置以及光衰减或散射问题的故障排除。在这项研究中，我们获得时间和空间分辨的液体体积分数的三维断层重建的整体平均消光图像产生独特的信息羽流运动和增长中的多羽流喷雾。测量进行了在一个恒定流的喷雾容器加上高速米氏散射，漫射背照明消光，和纹影成像。四种不同的燃料，单组分异辛烷、具有二异丁烯的多组分替代物、具有烯烃分子结构的多组分燃料和70%标准化汽油30%乙醇（e30）混合物，使用发动机燃烧网络（ECN）喷雾G喷射器在ECN G2下喷射（50 kPa绝对压力）、G3（100 kPa绝对压力）和G3 HT（G3，393 K环境温度）条件下。从断层重建的消光数据中获得的平面切片证实了闪速沸腾G2异辛烷条件下更大的羽流-羽流相互作用，与喷嘴钻孔角度相比，羽流方向相对于喷射器轴线的角度约小6°。烯烃和e30燃料，具有较宽的蒸馏曲线，表现出较强的羽流增长和最终完全喷雾羽流崩溃和较长的蒸发时间。使用3D数据集，我们表明，增加羽流增长的因素也创造了更多的羽流之间的相互作用，最终减少羽流方向角。
Understanding of plume direction and mixture quality in a combustion chamber is crucial to improve engine performance. While a variety of diagnostics using laser and x-ray facilities have been applied to identify plume direction, most applications require sophisticated experimental setup as well as troubleshooting for light attenuation or scattering issues. In this study, we acquire temporally and spatially resolved liquid volume fraction by three-dimensional tomographic reconstruction of ensemble-averaged extinction images to produce unique information on plume movement and growth in the midst of a multi-plume spray. Measurements were carried out in a constant-flow spray vessel coupled with high-speed Mie-scattering, diffused back-illumination extinction, and schlieren imaging. Four different fuels, a single componentiso-octane, a multi-component surrogate with di-isobutylene, a multi-component fuel with olefinic molecular structure, and a 70% standardized gasoline 30% ethanol (e30) blend were injected using Engine Combustion Network (ECN) Spray G injector under ECN G2 (50 kPa absolute), G3 (100 kPa absolute), and G3HT (G3 with 393 K ambient temperature) conditions. Planar slices, available from the tomographically reconstructed extinction data, confirmed greater plume-to-plume interaction for the flash-boiling G2iso-octane condition with an approximately 6°smaller plume direction angle relative to the injector axis, compared to the nozzle drill angle. The olefinic and e30 fuels, which have broader distillation curves, exhibited stronger plume growth and eventual complete spray plume collapse and longer time for evaporation. Using the 3D dataset, we show that factors that increase plume growth also create more interaction between plumes to ultimately reduce the plume direction angle.