基于X射线成像的喷油嘴内流特性试验  

Investigation on In-Nozzle Flow Characteristics Using X-Ray Imaging Technique

作　　者：高雅[1] 黄魏迪 李理光[1] 吴志军[1] Gao Ya;Huang Weidi;Li Liguang;Wu Zhijun(School of Automotive Studies,Tongji University,Shanghai 201804,China;Energy and Environment Department,National Institute of Advanced Industrial Science and Technology,Tsukuba 3058564,Japan)

机构地区：[1]同济大学汽车学院,上海201804 [2]日本产业技术综合研究所能源与环境部门,日本筑波市3058564

出　　处：《内燃机学报》2023年第5期458-465,共8页Transactions of Csice

基　　金：国家自然科学基金资助项目(51606060,U1832179);国家留学基金委资助项目(201506260017).

摘　　要：通过同步辐射X射线测量技术,开展了直喷汽油机喷油嘴实际针阀运动过程中的内流与液核破碎的试验观测研究.在不同X射线光源参数下对内流流场进行了连续图像拍摄,确定了最优拍摄技术方案.分析了不同喷射压力、不同喷孔结构下内流随针阀特性的变化规律,进而讨论了内流对射流液核破碎的影响.结果表明:随着针阀开度的增加,喷孔内会快速地形成挑射液流.挑射液流的宽度与喷孔入口的角度有关,与喷射压力无关.其原因与所采用喷油嘴的长径比较短有关.挑射液流会加速射流的液核破碎过程.喷孔内挑射液流的宽度增加会引起射流宽度的增大.The in-nozzle flow and near-nozzle spray characteristics of a gasoline nozzle under the actual needle motion were visualized using the synchrotron radiation X-ray imaging technique.Firstly,the X-ray light source parameters were carefully determined to obtain the most optimized imaging quality.Then,the experiments were conducted to observe the in-nozzle flow and liquid-core breakup simultaneously.Finally,their dependency was discussed accordingly.Investigating results show that the hydraulic flip is formed shortly as the needle opens.The hydraulic flip width is sensitive to the orifice inlet angle,whereas barely changes with injection pressures.This phenomenon could result from the short length-to-diameter ratio of the currently used nozzle.The existence of a hydraulic flip in the nozzle boosts the jet breakup.The jet spreads wider as the hydraulic-flip width increases.

关 键 词：缸内汽油直喷 同步辐射X射线成像 喷油嘴 内流流动特性 

分 类 号：TK411[动力工程及工程热物理—动力机械及工程]