汽油单液滴撞击不同壁面试验研究  

Experimental Study on Impingement of Single Gasoline Droplet on Different Substrates

作　　者：彭振山 裴毅强[1] 秦静[1,2] 卢莉莉 朱庆阳 彭志军[1] PENG Zhenshan;PEI Yiqiang;QIN Jing;LU Lili;ZHU Qingyang;PENG Zhijun(State Key Laboratory of Engines,Tianjin University,Tianjin 300072,China;Internal Combustion Engine Research Institute,Tianjin University,Tianjin 300072,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

出　　处：《内燃机工程》2019年第6期36-42,49,共8页Chinese Internal Combustion Engine Engineering

基　　金：国家自然科学基金重点项目(5167060387)~~

摘　　要：为明确汽油单液滴撞壁特性,设计了单液滴撞壁系统,分析了汽油液滴撞壁现象及不同壁面对汽油液滴撞壁结果转捩的影响。研究表明:汽油液滴撞击干壁面时在壁面粘附铺展成一层附壁油膜,附壁油膜促使液滴再次撞壁时发生皇冠射流飞溅现象。附壁油膜越薄,飞溅越剧烈,飞溅持续时间越短。相比硅油膜动力黏度,硅油膜厚度对汽油液滴撞壁后形态演变过程影响更大。汽油液滴撞击硅油膜会稀释硅油膜,稀释前后射流分别为碗状射流、皇冠状射流。随着稀释程度增加,皇冠状射流的二次液滴数量增加,二次液滴中含有壁面硅油组分。无量纲时间τ<1时,Rioboo模型能较好地预测铺展因子变化规律,但若超过此时间则Rioboo模型预测不准。In order to clarify the characteristics of single gasoline droplet impacting on different substrates,a single droplet impingement system was designed,and the effects of different substrates on impingement results were compared and studied.The results show that single gasoline droplet impacting on a dry wall is easy to deposit to form a gasoline film.The presence of the attached gasoline film will promote a crown jet splash phenomenon when the droplet hits the wall again,causing secondary droplets.The thinner the gasoline film is,the more violent the splash is and the shorter the duration of the splash is.Compared with the viscosity of a silicone oil film,the thickness has a greater influence on the morphological evolution of the gasoline droplet and silicone oil film after collision.When single gasoline droplet impacts on pure silicone oil films of different thicknesses and viscosities,there is no secondary droplets splash.However,the gasoline droplet will deposit and penetrate any silicone oil film and diluts the silicone oil.There is bowl splash before the dilution and crown jet splash after the dilution.The number of secondary droplets increases with the increase of the amount of gasoline in any silicone oil film.The secondary droplets contain silicone oil.The Rioboo model can better predict the variation law of the spreading factor when the dimensionless time is less than 1,but it can not predict accurately when the dimensionless time exceeds 1.

关 键 词：汽油 二次液滴 油膜 碰撞 飞溅 

分 类 号：TK411[动力工程及工程热物理—动力机械及工程]