汽油缸内直喷喷雾在不同壁温和二次喷射下的附壁油膜特性研究  

Study on Characteristics of Wall Fuel Film from Gasoline Direct Injection Spray with Two-Stage Injection at Different Surface Temperatures

作　　者：叶自旺 裴毅强[1] 郭瑞涛 彭志军[1] 秦静[1,2] 许锴 YE Ziwang;PEI Yiqiang;GUO Ruitao;PENG Zhijun;QIN Jing;XU Kai(State Key Laboratory of Engines,Tianjin University,Tianjin 300072,China;Internal Combustion Engine Research Institute,Tianjin University,Tianjin 300072,China;School of Mechanical Engineering,Guangxi University,Nanning 530004,China)

机构地区：[1]天津大学内燃机燃烧学国家重点实验室,天津300072 [2]天津大学内燃机研究所,天津300072 [3]广西大学机械工程学院,南宁530004

出　　处：《内燃机工程》2020年第3期1-8,共8页Chinese Internal Combustion Engine Engineering

基　　金：国家自然科学基金资助项目(51676136)

摘　　要：采用激光诱导荧光(laser induced fluorescence,LIF)法测量缸内直喷喷油器喷雾附壁油膜的厚度分布,研究了附壁油膜质量和平均厚度随不同的壁面温度和喷射策略的变化。结果表明:常温壁面下油膜呈“波浪状”,热壁面下油膜的边缘轮廓呈“带状”凸起,在壁面温度为413 K时,还出现了聚集的小液滴。保持总喷油量不变,随着壁面温度的增大,单次喷射的附壁油膜质量逐渐减小,二次喷射的附壁油膜质量先减小后增大,单/二次喷射的附壁油膜平均厚度都逐渐增大;相对于单次喷射,相同热壁面温度下的二次喷射附壁油膜平均厚度都较小,在壁面温度同为413 K时最多减小了42%。仅增加第二次喷射的喷油脉宽,壁面温度为298 K和373 K时的附壁油膜质量先增大后减小,壁面温度为413 K时附壁油膜质量逐渐增大;相同喷油脉宽下,壁面温度为413 K时附壁油膜平均厚度最大,而壁面温度为298 K和373 K时附壁油膜平均厚度与喷油间隔相关。The laser induced fluorescence(LIF)technique was used to investigate the thickness distribution of the fuel film of gasoline direct injection spray,and the variation of fuel film mass and mean fuel film thickness with different injection strategies and at different surface temperatures were studied.The results showed that fuel film at normal surface temperature was“wave-like”,while the edge of fuel film at the heated surface temperature was“stripe-like”and there were also some small droplets gathering at 413 K.Keeping the total fuel injection amount constant,with the increase of the surface temperature,the fuel film mass of single injection decreased gradually,and that of two-stage injection decreased first and then increased,but the mean fuel film thickness became great with either single or two-stage injection strategy.Compared with the single injection,the mean fuel film thickness in the two-stage injection was smaller at the same heated surface temperature,and the maximum reduction was 42%at the same surface temperature of 413 K.Just changing the second injection duration,with the increase of the second injection duration,the fuel film mass increased first and then decreased when the surface temperature was 298 K and 373 K,and the fuel film mass at the surface temperature of 413 K increased gradually.Just changing the second injection duration and keeping the same second injection duration at different surface temperatures,the mean fuel film thickness at the surface temperature of 413 K was the largest at each injection interval,and the mean fuel film thicknesses at the surface temperatures of 298 K and 373 K were subject to the injection interval.

关 键 词：缸内直喷 壁面温度 二次喷射 附壁油膜质量 附壁油膜平均厚度 

分 类 号：TK418.9[动力工程及工程热物理—动力机械及工程]