高压环境下水滴碰撞动力学研究
Study on Water Droplet Collision Dynamics Under High Ambient Pressure
张宸玮 1章振宇1
作者信息
- 1. 北京理工大学机械与车辆学院,北京,100081
- 折叠
摘要
考虑到发动机燃烧室内的真实环境,搭建了高压环境下液滴碰撞试验系统.通过高速相机与长焦显微镜头的组合首次实现了较高环境压力下液滴碰撞过程的拍摄并得到高清水滴碰撞图像.基于拍摄得到的图像,开发了一套数据处理方法,完成了液滴碰撞过程中碰撞韦伯数We与碰撞参数B的量化,并得到了用于分析液滴碰撞结果的We-B诺谟图.发现当水滴碰撞的环境压力较小时,碰撞结果有融合、拉伸分离与反向分离;但当碰撞的环境压力逐渐升高,水滴碰撞后出现了"弹开"的现象.随后参考Estrade等对液滴碰撞结果的分析,将液滴碰撞后的形状因子进行修正,并将环境压力的影响考虑在内,得到了不同环境压力下液滴碰撞后融合与弹开的分界线,实现了与试验数据的高度吻合.
Abstract
A droplet collision experimental system was established considering the real environ-ment in an engine combustion chamber.The combination of a high-speed camera with a telephoto microscope lens was used to capture the droplet collision process under high ambient pressure for the first time,and high-resolution droplet collision images using water as the medium were obtained.Based on the captured images,a set of data processing methods was developed to quantify the collision Weber number We and collision parameter B,then the processed data was plotted on a We-B nomograph for analyzing.It is found that when the environmental pressure is low,there are coalescence,stretching separation,and reflective separation results as the collision Weber number and collision parameters change.However,when the ambient pressure gradually increases,the water droplets appear to"bouncing off"after collision.Subsequently,the shape factor of the droplet after collision was corrected,and the influence of environmental pressure was taken into account referring to the analysis of droplet collision boundary by Estrade et al.Finally,the boundary between coales-cence and bouncing under different environmental pressures was obtained,achieving a high degree of agreement with experimental data.
关键词
液滴碰撞/弹开/高压/形状因子Key words
droplet collision/bouncing/high ambient pressure/shape factor引用本文复制引用
基金项目
国家自然科学基金资助项目(51806013)
国家自然科学基金资助项目(12072194)
出版年
2024
NETL
NSTL
维普
万方数据