Abstract：Cavitation phenomenon of the hole with instability, the generation of a hole and collapse induce the disturbance of fluid flow in the high-pressure spray hole, diesel injector nozzle hole Shigao pressure jet orifice of the typical form. By using the ANSYS software of fluent module, we simulate diesel injector under the different conditions of injection pressure, spray holes with different inlet rounded radii, diameter ratio inside the nozzle fuel hole shape, and we analyze the influence of the nozzle structure parameters on the fuel mass flow in the presence of cavitation. The results show that in certain circumstances, the injection pressure can be increased by increasing the inlet radius and changing the medium-diameter ratio as d/D<1.0 or d/D>1.1, which can inhibit the cavitation, and 1.0<d/D<1.1 can promote the cavitation. Increasing the inlet radius and the radius ratio of the nozzle can increase the mass flow rate of the fuel in the injection hole, and the effect is more obvious when the injection pressure is higher.
王鹏, 王忠, 瞿磊. 高压喷射喷孔结构参数对空化现象的影响[J]. 排灌机械工程学报, 2017, 35(12): 1063-1068.
WANG Peng, WANG Zhong, QU Lei. Influence of structure parameters of high-pressure jet nozzle on cavitation. Journal of Drainage and Irrigation Machinery Engin, 2017, 35(12): 1063-1068.
[1]BUTCHER A J, ALEIFERIS P G, RICHARDSON D. Development of a real-size optical injector nozzle for studies of cavitation, spray formation and flash-boiling at conditions relevant to direct-injection spark-ignition engines[J]. International journal of engine research, 2013, 14(6):557-577.[2]PAYRI R, GARCíA J M, SALVADOR FJ, et al. Using spray momentum flux measurements to understand the influence of diesel nozzle geometry on spray characteristics[J]. Fuel, 2005,84(5):551-561.[3]SOM S,RAMIREZ A I,LONGMAN D E,et al. Effect of nozzle orifice geometry on spray, combustion, and emission characteristics under diesel engine conditions [J]. Fuel,2011,90(3):1267-1276.[4]MOON S,GAO Y,WANG J,et al. Near-field dynamics of high-speed diesel sprays:Effects of orifice inlet geo-metry and injection pressure [J]. Fuel,2014,133(5):299-309.[5]田春霞,王启航,张克文,等. 喷油嘴喷孔内气液两相流动的三维模拟[J]. 柴油机设计与制造,2008(3):10-15,20. TIAN Chunxia,WANG Qihang,ZHANG Kewen,et al. Three dimensional simulation of gas liquid two phase flow in nozzle orifice[J]. Design and manufacture of diesel engine,2008(3):10-15,20.(in Chinese)[6]卢国权,虞钢,何秀丽,等. 喷孔几何特征对变截面喷油孔空穴流动状态的影响[J]. 内燃机学报,2012(3):254-259. LU Guoquan,YU Gang,He Xiuli,et al. Effect of geometry characteristics on internal cavitation flow of injection nozzle with varying hole cross-section[J]. Transactions of CSICE,2012(3):254-259.(in Chinese)[7]李德镇. 喷嘴燃油流动特性模拟研究与参数优化[D].太原:太原理工大学,2013.[8]SHERVANI M T, PARSA S, GHORBANI M. Numerical study on the effect of the cavitation phenomenon on the characteristics of fuel spray[J]. Mathematical & computer modelling, 2012, 56(S5/6):105-117.[9]HE Zhixia,ZHONG Wenjun,WANG Qian,et al. Effect of nozzle geometrical and dynamic factors on cavitating and turbulent flow in a diesel multi-hole injector nozzle[J].International journal of thermal sciences,2013,70(8):132-143.[10]何勇灵,丁川. 喷油器瞬态两相流动的建模方法[J]. 北京航空航天大学学报,2012,38(1):6-10. HE Yongling,DING Chuan. Method of modeling tran-sient two-phase flow in injector[J]. Journal of Beijing University of Aeronautics and Astronautics,2012,38(1):6-10.(in Chinese)[11]杨瑞龙. 喷油系统气穴流动及燃油特性分析[D].武汉:华中科技大学,2006.[12]王谦,李念,何志霞,等. 柴油机双层多孔喷油嘴内部空穴两相流动研究[J]. 江苏大学学报(自然科学版),2015,36(2):142-147. WANG Qian,Li Nian,HE Zhixia,et al. Cavity flow in double-layer multi-holes diesel injector nozzle[J]. Journal of Jiangsu University(natural science edition), 2015,36(2):142-147.(in Chinese)[13]MARTIN K,MARWAN A, AHMED M. Micro-drilling in steel using ultra-short pulsed laser beams with radial and azimuthal polarization[J]. Optics express,2010,18(21):22305-22313.
