某喷油器喷孔内流穴蚀风险及疲劳寿命分析  

Analysis of flow cavitation risk and fatigue life in the nozzle hole of an injector

作　　者：许磊 张翼[1] 张宇[1] 庞浩宇 宋猛 Xu Lei;Zhang Yi;Zhang Yu;Pang Haoyu;Song Meng(College of Energy and Power Engineering,North University of China,Shanxi Taiyuan,030051,China)

机构地区：[1]中北大学能源与动力工程学院,山西太原030051

出　　处：《机械设计与制造工程》2022年第3期13-17,共5页Machine Design and Manufacturing Engineering

摘　　要：为改善喷油器喷孔长期运行容易引起的穴蚀破坏问题,基于计算流体力学、空化穴蚀疲劳理论,通过Fluent软件中的UDF模块引入单气泡破裂对壁面影响经验公式,建立喷油器喷孔内流的经验公式穴蚀风险仿真模型。然后引入Workbench中Ncode模块针对喷孔寿命进行分析,研究不同喷孔几何形状、不同最大针阀升程对喷油器喷孔寿命的影响。经R_(rs)模型检验可知,经验公式穴蚀风险仿真模型具有可靠性。穴蚀损伤较大区域集中于喷孔入口处,相比于喷孔圆锥度的增加,最大针阀升程的降低对喷孔内壁面寿命所造成影响较小,故可优先调整喷孔的圆锥度以提高喷嘴的寿命。In order to improve the cavitation damage caused by long-term operation of the injector orifice,based on computational fluid dynamics and cavitation fatigue theory,this paper introduces the empirical formula of the impact of single bubble rupture on the wall through the UDF module in Fluent software,and establishes the empirical formula cavitation risk simulation model of the flow in the injector orifice.The simulation results of the empirical formula simulation model are compared with the simulation results of the R_(rs) model verified by experiments.The location trend of cavitation damage obtained by the two models is consistent.Then,the Ncode module in workbench is introduced to analyze the nozzle life,and calculate the influence of different nozzle geometry and different needle valve lift on the nozzle life of the injector.R_(rs) model test shows that the empirical formula cavitation risk simulation model introduced in this paper is reliable.The area with large cavitation risk is mainly concentrated at the inlet of the spray hole.Compared with the increase of the taper of the spray hole,the decrease of the maximum needle valve lift has less impact on the service life of the inner wall of the spray hole.Therefore,the taper of the spray hole can be adjusted first to improve the service life of the nozzle.

关 键 词：喷油器喷嘴 疲劳寿命 空化 穴蚀 

分 类 号：TH117[机械工程—机械设计及理论]