Needle motion and its influence on in-nozzle flow and spray jet characteristics

被引：0
|
作者：
Zhao W.-B. [1 ]
Li Y.-J. [1 ]
Deng J. [1 ]
Li L.-G. [1 ]
Wu Z.-J. [1 ]
机构：
[1] School of Automotive Studies, Tongji University, Shanghai
来源：
Jilin Daxue Xuebao (Gongxueban)/Journal of Jilin University (Engineering and Technology Edition) | 2022年 / 52卷 / 10期
关键词：
cavitation; hole-to-hole flow non-uniformity; needle motion; nozzle inflow; power machinery and engineering; ultrafast X-ray imaging;
D O I：
10.13229/j.cnki.jdxbgxb20210316
中图分类号：
学科分类号：
摘要：
Needle dynamic characteristics and the influence of control current on needle motion about gasoline direct injection （GDI） nozzle were researched based on ultrafast X-ray imaging technology. Transient characteristics of in-nozzle flow and near-field spray jets during needle lift process and effects of cavitation were simulated based on a standard 8-hole GDI nozzle. A real needle motion profile obtained by ultrafast X-ray imaging technology was applied to reflect the influence of needle lateral vibration on hole-to-hole non-uniformity. The experimental results show that vibration occurs when needle module collides with iron core in the opening stage and with needle seat in the closing stage，which makes it difficult to control fuel injection precisely. Reduction of control current contributes to less vibration and more precise fuel injection. The simulation results show that cavitation at the upper face of nozzle leads to hydraulic flip phenomenon，so the fuel jet deviates from nozzle axis. Such kind of jet deflection is enhanced by intense entrainment between the jet and the ambient gas，and the maximum deflection angle is up to 5°. The jet deflection will cause nozzle tip wetting at the lower boundary of the contour-bore surface，which will deteriorate the engine particle emissions performance. The study also indicates that the lateral vibration of needle results in non-uniform flow characteristics between different holes，and such non-uniformity decreases as the needle lifts higher. © 2022 Editorial Board of Jilin University. All rights reserved.
引用
收藏
页码：2234 / 2243
页数：9
相关论文
共 22 条
  • [1] Yao Zhi-liang, Zhang Ming-hui, Wang Xin-tong, Et al., Trends in vehicular emissions in typical cities in China, China Environmental Science, 32, 9, pp. 1565-1573, (2012)
  • [2] He Zhi-xia, Zhang Xin, Tao Xi-cheng, Et al., Experimental study into effects of fuel temperature on diesel injection process, Transactions of CSICE, 35, 5, pp. 399-405, (2017)
  • [3] Zhang Zheng-yang, He Zhi-xia, Guo Gen-miao, Et al., Experiment of transient cavitating flow in the real-size diesel injector nozzle, Transactions of CSICE, 35, 2, pp. 136-141, (2017)
  • [4] Huang Hao-zhong, Shi Cheng, Zhang Peng, Et al., Effect of injection pressure and ambient pressure on spray characteristics of pine oil-diesel blends, Transactions of the Chinese Society of Agricultural Engineering, 32, 17, pp. 55-61, (2016)
  • [5] Zhu Xi, Zhang Zhen-dong, Cheng Qiang, Numerical simulation and experimental study for spray characteristics of the gasoline direct injection (gdi) multi-hole injector, Chinese Internal Combustion Engine Engineering, 36, 6, pp. 137-143, (2015)
  • [6] Wu Yu-qiang, Wang Qian, Gao Zhi-sheng, Et al., The effect of asymmetric nozzle hole geometry of a diesel nozzle on the near-field spray characteristics, Chinese Internal Combustion Engine Engineering, 37, 6, pp. 170-175, (2016)
  • [7] Payri R, Viera J P, Gopalakrishnan V, Et al., The effect of nozzle geometry over the evaporative spray formation for three different fuels, Fuel, 188, pp. 645-660, (2017)
  • [8] Shi Dong-xiao, Zhou Zhen, Guo Li-xin, Et al., Visu⁃ alization of cavitating flow in diesel injector nozzles and its effects on spray, Transactions of CSICE, 37, 1, pp. 54-59, (2019)
  • [9] Torelli R, Som S, Pei Y, Et al., Influence of fuel properties on internal nozzle flow development in a multi-hole diesel injector, Fuel, 204, pp. 171-184, (2017)
  • [10] Xie Fang-xi, Yao Zhuo-tong, Hu Xue-song, Et al., Influence of dynamic change of needle and hydraulic pressure in diesel injection nozzle on fuel spray charac⁃ teristic, Journal of Jilin University (Engineering and Technology Edition), 43, 4, pp. 897-902, (2013)
123