Journal of Jilin University(Engineering and Technology Edition) ›› 2022, Vol. 52 ›› Issue (10): 2234-2243.doi: 10.13229/j.cnki.jdxbgxb20210316

Previous Articles    

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

Wen-bo ZHAO(),Yu-jie LI,Jun DENG,Li-guang LI,Zhi-jun WU()   

  1. School of Automotive Studies，Tongji University，Shanghai 201804，China
  • Received:2021-04-12 Online:2022-10-01 Published:2022-11-11
  • Contact: Zhi-jun WU E-mail:0713_zhaowenbo@tongji.edu.cn;zjwu@tongji.edu.cn

RICH HTML

 3   

PDF (PC)

686

Abstract:

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.

Key words: power machinery and engineering, needle motion, ultrafast X-ray imaging, nozzle inflow, cavitation, hole-to-hole flow non-uniformity

CLC Number: 

  • TK411

Fig.1

Needle motion measurement platform"

Fig.2

Image acquisition direction schematic"

Table 1

High-speed camera parameters"

相机参数数值
帧率/（帧·s-1）40000
曝光时间/μs23.4
图像像素/pixel1024×512
像素尺寸/（μm·pixel-1）2.5

Fig.3

Cross-correlation algorithm window settings"

Fig.4

Schematic diagram of control current"

Table 2

Experimental schemes of current value effects"

Il /ATl /msIh /ATh /ms
方案160.551.5
方案270.551.5
方案3100.551.5

Table 3

Experimental schemes of current durationeffects"

Il/ATl/msIh/ATh/ms
方案160.551.5
方案1h60.552.0
方案1l61.051.5

Fig.5

Measured needle motion curve"

Fig.6

Needle lift curves under different current values"

Fig.7

Needle lift curves under different current"

Fig.8

Geometric model of spray G"

Table 4

Nozzle structure parameters"

参 数数 值
喷油孔数量8
沉孔直径/mm0.388
沉孔长度/mm0.480
喷孔直径/mm0.165
喷孔长度/mm0.160
喷油孔轴线与喷嘴轴线夹角/（°）37

Fig.9

Schematic diagram of mesh setup"

Fig.10

Actual and theoretical needle valve lift curves"

Fig.11

Measured curve of needle valve lateral vibration"

Fig.12

Measured mass flow curve ［19］"

Fig.13

Pressure and differential pressure curves"

Table 5

Definition of different needle lifting stages"

阶段时间/ms
10.292~0.300
20.300~0.312
30.312~0.324
40.324~0.340

Fig.14

Nozzle internal flow characteristics of stage 1"

Fig.15

Nozzle internal flow characteristics of stage 2"

Fig.16

Velocity distribution at t=0.312 ms in stage 2"

Fig.17

Nozzle internal flow characteristics of stage 3"

Fig.18

Nozzle internal flow characteristics of stage 4"

Fig.19

Velocity distribution at z=0 section of both ideal and measured cases"

Fig.20

Velocity contour of contour bore outlet of both ideal and measured cases"

Fig.21

Turbulent kinetic energy contour of contour bore outlet of both ideal and measured cases"

Fig.22

Mean flow velocity difference between nozzle 2 and nozzle 6"

1 姚志良,张明辉,王新彤,等. 中国典型城市机动车排放演变趋势[J]. 中国环境科学, 2012, 32(9): 1565-1573.
Yao Zhi-liang, Zhang Ming-hui, Wang Xin-tong, et al. Trends in vehicular emissions in typical cities in China[J]. China Environmental Science, 2012, 32(9): 1565-1573.
2 何志霞,张鑫,陶希成,等. 燃油温度对柴油喷射过程影响的试验[J]. 内燃机学报, 2017, 35(5): 399-405.
He Zhi-xia, Zhang Xin, Tao Xi-cheng, et al. Experimental study into effects of fuel temperature on diesel injection process[J]. Transactions of CSICE, 2017, 35(5): 399-405.
3 张正洋,何志霞,郭根苗,等. 柴油机原型喷嘴内瞬态流动的特性试验[J]. 内燃机学报, 2017, 35(2): 136-141.
Zhang Zheng-yang, He Zhi-xia, Guo Gen-miao, et al. Experiment of transient cavitating flow in the real-size diesel injector nozzle[J]. Transactions of CSICE, 2017, 35(2): 136-141.
4 黄豪中,史程,张鹏,等. 喷射压力及环境背压对松油-柴油混合燃料喷雾特性的影响[J]. 农业工程学报, 2016, 32(17): 55-61.
Huang Hao-zhong, Shi Cheng, Zhang Peng, et al. Effect of injection pressure and ambient pressure on spray characteristics of pine oil-diesel blends[J]. Transactions of the Chinese Society of Agricultural Engineering, 2016, 32(17): 55-61.
5 朱希,张振东,程强. GDI多孔喷油器喷雾特性的试验与仿真研究[J]. 内燃机工程, 2015, 36(6): 137-143.
Zhu Xi, Zhang Zhen-dong, Cheng Qiang. Numerical simulation and experimental study for spray characteristics of the gasoline direct injection (gdi) multi-hole injector [J]. Chinese Internal Combustion Engine Engineering, 2015, 36(6): 137-143.
6 吴玉强,王谦,高志胜,等. 柴油机喷嘴喷孔非对称结构对近场喷雾特性的影响[J]. 内燃机工程, 2016, 37(6): 170-175.
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 [J]. Chinese Internal Combustion Engine Engineering, 2016, 37(6): 170-175.
7 Payri R, Viera J P, Gopalakrishnan V, et al. The effect of nozzle geometry over the evaporative spray formation for three different fuels[J]. Fuel, 2017, 188: 645-660.
8 施东晓,周禛,郭立新,等. 喷油嘴空穴流动可视化及其对喷雾的影响[J]. 内燃机学报, 2019, 37(1): 54-59.
Shi Dong-xiao, Zhou Zhen, Guo Li-xin, et al. Visualization of cavitating flow in diesel injector nozzles and its effects on spray[J]. Transactions of CSICE, 2019, 37(1): 54-59.
9 Torelli R, Som S, Pei Y, et al. Influence of fuel properties on internal nozzle flow development in a multi-hole diesel injector[J]. Fuel, 2017, 204: 171-184.
10 解方喜,姚卓彤,胡雪松,等. 针阀运动和油压波动对燃油喷雾特性的影响[J]. 吉林大学学报:工学版, 2013, 43(4): 897-902.
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 characteristic[J]. Journal of Jilin University (Engineering and Technology Edition), 2013, 43(4): 897-902.
11 何志霞,钟汶君,黄云龙,等. 针阀运动对柴油机喷嘴瞬态流动特性的影响[J]. 内燃机学报, 2012, 30(4): 336-342.
He Zhi-xia, Zhong Wen-jun, Huang Yun-long, et al. Investigation of transient behavior of cavitation flow in injector nozzles affected by the needle movement[J]. Transactions of CSICE, 2012, 30(4): 336-342.
12 张现成,许伯彦. 考虑针阀运动的LPG高压旋流喷油器内外流动过程的数值解析[J].内燃机学报, 2013, 31(3): 228-234.
Zhang Xian-cheng, Xu Bo-yan. Numerical analysis of internal flow and spray for a lpg high pressure swirl injector with needle movement[J]. Transactions of Csice, 2013, 31(3): 228-234.
13 Wang X S, Chen B, Wang R, et al. Experimental study on the relation between internal flow and flashing spray characteristics of R134a using straight tube nozzles[J]. International Journal of Heat and Mass Transfer, 2017, 115(B): 524-536.
14 肖体乔,谢红兰,邓彪,等. 上海光源X射线成像及其应用研究进展[J]. 光学学报, 2014, 34(1): 9-23.
Xiao Ti-qiao, Xie Hong-lan, Deng Biao, et al. Progresses of X-Ray imaging methodology and its applications at shanghai synchrotron radiation facility[J]. Acta Optica Sinica, 2014, 34(1): 9-23.
15 陈洁. 高分辨率X射线成像技术与应用研究[D]. 合肥:中国科学技术大学核科学技术学院, 2010.
Cheng Jie. Research on high resolution X-ray imaging technology and application[D]. Hefei: School of Nuclear Science and Technology, University of Science and Technology of China, 2010.
16 陈荣昌,杜国浩,谢红兰,等. 上海光源X射线成像实验站相位衬度CT初步结果[J]. 核技术, 2009, 32(4): 241-245.
Chen Rong-chang, Du Guo-hao, Xie Hong-lan, et al. Preliminary results for X-ray phase contrast micro-tomography on the biomedical imaging beamline at SSRF[J]. Nuclear Techniques, 2009, 32(4): 241-245.
17 Shields B, Neroorkar K, and Schmidt D P, et al. Cavitation as rapid flash boiling[C]∥Americas 23rd Annual Conference on Liquid Atomization and Spray Systems, Ventura, USA, 2011: 1-7.
18 Powell Chris. Measured needle motion (x-ray phase contrast)[EB/OL]. [2021-04-21]..
19 Parrish Scott. Rate of injection (tube method)[EB/OL]. [2021-04-21]..
20 Huang W, Moon S, Wang J, et al. Nozzle tip wetting in gasoline direct injection injector and its link with nozzle internal flow[J]. International Journal of Engine Research, 2020, 21(2): 340-351.
21 Peterson K, Grover R, Mitcham C. Application of optical diagnostics and simulation to fuel injector tip wetting and soot production[C]∥Proceeding of the 11th International Symposium on Combustion Diagnostics, Baden,Germany, 2014: 79-84.
22 Oude N D, Freeland P, Behringer M, et al. Developing low gasoline particulate emission engines through improved fuel delivery[C]∥SAE Paper, 2014-01-2843.
[1] Yan ZHANG,Wei LIU,Shu-yong ZHANG,Yi-qiang PEI,Meng-meng DONG,Jing QIN. Optimization on thermal load of combustion chamber on two/four⁃stroke switchable diesel engine [J]. Journal of Jilin University(Engineering and Technology Edition), 2022, 52(3): 504-514.
[2] Bin ZHANG,Guo-zan CHENG,Hao-cen HONG,Chun-Xiao ZHAO,Hua-yong YANG. Cavitation mechanism of double⁃acting vane pump based on computational fluid dynamics simulation method [J]. Journal of Jilin University(Engineering and Technology Edition), 2021, 51(3): 831-839.
[3] Zhi-jun LI,Hao LIU,Li-peng ZHANG,Zhen-guo LI,Yuan-kai SHAO,Zhi-yang LI. Simulation on influence of microstructure of the wall on deep bed filtration of particulate filter [J]. Journal of Jilin University(Engineering and Technology Edition), 2021, 51(2): 422-434.
[4] Jian WANG,Xin XU,Han GU,Duo-jun ZHANG,Sheng-ji LIU. Heating characteristics of DOC based on exhaust thermal management of diesel engine [J]. Journal of Jilin University(Engineering and Technology Edition), 2020, 50(2): 408-416.
[5] Chang-qing SONG,Wen-miao CHEN,Jun LI,Da-wei QU,Hao CUI. Effects of single and dual ignition on combustion characteristics of natural gas under different equivalence ratios [J]. Journal of Jilin University(Engineering and Technology Edition), 2019, 49(6): 1929-1935.
[6] Yi-xiao ZHU,Xiao-min HE,Yi JIN. Effects of radial strut width on flow structure ofsingle⁃cavity trapped vortex combustor [J]. Journal of Jilin University(Engineering and Technology Edition), 2019, 49(6): 1936-1944.
[7] Qiao WANG,Wan-chen SUN,Liang GUO,Peng CHENG,Lu-yan FAN,Guo-liang LI. Effects of butanol/diesel blends on combustion and particulate emission characteristics of compression ignition engine [J]. Journal of Jilin University(Engineering and Technology Edition), 2019, 49(6): 1920-1928.
[8] Chang-cheng LIU,Zhong-chang LIU,Jing TIAN,Yun XU,Ze-yu YANG. In⁃cylinder exergy destruction during combustion process ofheavy⁃duty turbocharged diesel engine [J]. Journal of Jilin University(Engineering and Technology Edition), 2019, 49(6): 1911-1919.
[9] Xiao-yu HU,Guo-xiang LI,Shu-zhan BAI,Ke SUN,Si-yuan LI. Modified boiling heat transfer model considering roughness and material of heating surface [J]. Journal of Jilin University(Engineering and Technology Edition), 2019, 49(6): 1945-1950.
[10] De⁃jun WANG,Zhi⁃chao LYU,Qi⁃ming WANG,Jian⁃rui ZHANG,Jian⁃nan DING. Cylinder pressure identification based on EKF and frequency⁃amplitude modulation Fourier series [J]. Journal of Jilin University(Engineering and Technology Edition), 2019, 49(4): 1174-1185.
[11] Peng⁃fei ZANG,Zhe WANG,Yang GAO,Chen⁃le SUN. Investigation of integrated control strategy for stable operation of linear generator/engine system [J]. Journal of Jilin University(Engineering and Technology Edition), 2019, 49(3): 798-804.
[12] JIANG Tao,LIN Xue-dong,LI De-gang,YANG Miao,TANG Xue-lin. Effect of control parameters on heat release rate with ANN method [J]. Journal of Jilin University(Engineering and Technology Edition), 2018, 48(6): 1747-1754.
[13] LIN Xue-dong, JIANG Tao, XU Tao, LI De-gang, GUO Liang. Control strategy of high pressure pump in starting condition of high pressure common rail diesel engine [J]. Journal of Jilin University(Engineering and Technology Edition), 2018, 48(5): 1436-1443.
[14] LI Zhi-jun, WANG Hao, HE Li, CAO Li-juan, ZHANG Yu-chi, ZHAO Xin-shun. Soot distribution features and its influence factors in catalytic diesel particulate filte [J]. Journal of Jilin University(Engineering and Technology Edition), 2018, 48(5): 1466-1474.
[15] QIN Jing, XU He, PEI Yi-qiang, ZUO Zi-nong, LU Li-li. Influence of initial temperature and initial pressure on premixed laminar burning characteristics of methane-dissociated methanol flames [J]. Journal of Jilin University(Engineering and Technology Edition), 2018, 48(5): 1475-1482.
Viewed
Full text


Abstract

Cited
  Shared   
  Discussed   
No Suggested Reading articles found!
Copyright © Journal of Jilin University(Engineering and Technology Edition), All Rights Reserved.
Tel: +86-431-85095297　Fax: +86-431-85094074　E-mail: xbgxb@jlu.edu.cn
Powered by Beijing Magtech Co. Ltd