Experimental study on fusion and break-up motion after droplet collision

doi:10.1016/j.cjche.2019.09.002

中国化学工程学报 ›› 2020, Vol. 28 ›› Issue (3): 712-720.DOI: 10.1016/j.cjche.2019.09.002

• Fluid Dynamics and Transport Phenomena • 上一篇下一篇

Experimental study on fusion and break-up motion after droplet collision

Yi Li, Zhi Ning, Ming Lü

Beijing Jiaotong University, School of Mechanical, Electronic and Control Engineering, Beijing 100044, China;Beijing Jiaotong University, Beijing Key Lab Powertrain New Energy Vehicle, Beijing 100044, China

收稿日期:2019-02-18 修回日期:2019-09-03 出版日期:2020-03-28 发布日期:2020-06-11
通讯作者: Zhi Ning, Ming Lü
基金资助:
Project supported by the National Natural Science Foundation of China (Grant Nos. 51776016, 51606006), Beijing Natural Science Foundation (Grant Nos. 3172025, 3182030), National Key Research and Development Program (Grant No. 2017YFB0103401), National Engineering Laboratory for Mobile Source Emission Control Technology (Grant No. NELMS2017A10), and the Talents Foundation of Beijing Jiaotong University (Grant No. 2018RC017).

Experimental study on fusion and break-up motion after droplet collision

Yi Li, Zhi Ning, Ming Lü

Beijing Jiaotong University, School of Mechanical, Electronic and Control Engineering, Beijing 100044, China;Beijing Jiaotong University, Beijing Key Lab Powertrain New Energy Vehicle, Beijing 100044, China

Received:2019-02-18 Revised:2019-09-03 Online:2020-03-28 Published:2020-06-11
Contact: Zhi Ning, Ming Lü
Supported by:
Project supported by the National Natural Science Foundation of China (Grant Nos. 51776016, 51606006), Beijing Natural Science Foundation (Grant Nos. 3172025, 3182030), National Key Research and Development Program (Grant No. 2017YFB0103401), National Engineering Laboratory for Mobile Source Emission Control Technology (Grant No. NELMS2017A10), and the Talents Foundation of Beijing Jiaotong University (Grant No. 2018RC017).

摘要/Abstract

摘要： The interactions between droplets have an important influence on the atomization of liquid fuel, the combustion efficiency, and the reduction of particulate matter emissions for an engine. For this reason, this paper presents results from an experimental study on the coalescence and break-up of droplets after collision. According to the shape and parameters of the droplets at different times after the collision of the droplets was captured by a high speed camera, analysis was done for the following effects of droplet collisions: the collision-coalescence motion for the collision between the droplets, the change history of the dimensionless length-to-width ratio of the oscillation motion, the critical size ratio of the breakup motion, and the liquid physical properties of the particles. The results show that the droplets collide and exhibit two forms of coalescence oscillation and break-up: for oscillating motion, at higher droplet collision velocities and dimensionless size ratios, there will be a larger dimensionless length-to-width ratio for the droplet oscillation; for the break-up motion, at higher collision velocities, there will be lower dimensionless size ratios, and lower liquid surface tension, shorter times over which the droplet breaks, and facilitated droplet break-up. The research results presented here can be used for atomization in engine cylinder, increasing the gas/liquid contact area and enhancing the combustion efficiency of gas/liquid heat transfer to improve the combustion efficiency of the engine.

关键词: Collision between droplets, Size ratio, Collision velocity, Broken moment

Abstract: The interactions between droplets have an important influence on the atomization of liquid fuel, the combustion efficiency, and the reduction of particulate matter emissions for an engine. For this reason, this paper presents results from an experimental study on the coalescence and break-up of droplets after collision. According to the shape and parameters of the droplets at different times after the collision of the droplets was captured by a high speed camera, analysis was done for the following effects of droplet collisions: the collision-coalescence motion for the collision between the droplets, the change history of the dimensionless length-to-width ratio of the oscillation motion, the critical size ratio of the breakup motion, and the liquid physical properties of the particles. The results show that the droplets collide and exhibit two forms of coalescence oscillation and break-up: for oscillating motion, at higher droplet collision velocities and dimensionless size ratios, there will be a larger dimensionless length-to-width ratio for the droplet oscillation; for the break-up motion, at higher collision velocities, there will be lower dimensionless size ratios, and lower liquid surface tension, shorter times over which the droplet breaks, and facilitated droplet break-up. The research results presented here can be used for atomization in engine cylinder, increasing the gas/liquid contact area and enhancing the combustion efficiency of gas/liquid heat transfer to improve the combustion efficiency of the engine.

Key words: Collision between droplets, Size ratio, Collision velocity, Broken moment

Yi Li, Zhi Ning, Ming Lü. Experimental study on fusion and break-up motion after droplet collision[J]. 中国化学工程学报, 2020, 28(3): 712-720.

Yi Li, Zhi Ning, Ming Lü. Experimental study on fusion and break-up motion after droplet collision[J]. Chinese Journal of Chemical Engineering, 2020, 28(3): 712-720.

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Experimental study on fusion and break-up motion after droplet collision

Experimental study on fusion and break-up motion after droplet collision

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