摘要
对静止空气中液体轴对称抛撒的首次破碎及二次破碎进行了实验研究,通过纹影装置获得其首次破碎及二次破碎发展过程的纹影照片,通过激光散射粒子直径测量仪获得了二次破碎所形成雾化场的Sauter平均直径(SMD)随时间和空间的分布。实验结果表明,由于“Rayleigh-Taylor不稳定性”的发展,在液体抛撒所形成液核的前端发生了具有波浪形的首次破碎,首次破碎所形成球形液体颗粒的直径与发生首次破碎的液核前端的液体薄层厚度基本相当。由于不同直径液体雾滴的速度弛豫时间的差异,导致二次破碎后的雾化场具有大雾滴在前、小雾滴在后的特征。同时,由于实验液体具有高挥发性,导致与轴线的距离超出某一范围后,二次破碎所形成的雾化场又会出现雾滴的SMD随距离的增加而逐渐减小的趋势。
This paper studies the primary breakup and secondary breakup of axisymmetrical dissemination of liquid. Schlieren apparatus was used to visualize the dissemination procedure, laser scattering apparatus was used to measure the Sauter Mean Diameter （SMD） of atomization field which was formed by secondary breakup. The results showed that because of the increase of ＂Rayleigh-Taylor instability＂, the undulant wavelike breakup was taken place at the front-end of liquid core. The diameter of spherical particles which were generated by primary breakup was equivalent to the thickness of the front-end of liquid core. Because of the difference of relaxation time of velocity, it had been happened that the droplets with larger diameter moved at the front of the atomization field and the smaller moved behind them. By reason of the high volatility of experimental liquid, SMD of the atomization field decreased with the increase of the distance of the observing point to the spray nozzle.
出处
《实验流体力学》
EI
CAS
CSCD
北大核心
2007年第2期50-55,共6页
Journal of Experiments in Fluid Mechanics
基金
深圳大学科研启动基金2006016资助项目
关键词
首次破碎
二次破碎
雾化场
SMD
液体抛撤
primary breakup
secondary breakup
atomization field
SMD
dissemination of liquid
