不同气液流量下喷射器内液滴特性分析

Droplets'characteristics in the ejector under different gas and liquid flow rate

单重态氧是氧碘化学激光的能量来源,其反应生成效率直接影响COIL输出的激光功率和光束质量。单重态氧的反应生成效率取决于气液接触面积,喷射式单重态氧生成器的气液接触面积与喷射器内的液滴分布有关。本文利用商业计算流体力学软件Fluent 6.3,对喷射式单重态氧发生器内不同气液流量情况下的液滴直径、速度分布规律进行模拟。模拟过程主动流体为水,被动流体为氯气和氦气的混合气体,通过模拟得出了不同气液流量情况下,喷射器内液滴的直径、速度分布情况。在液相流率不变的情况下,随气相流率的增大,喷射器内的液滴平均直径减小,平均速度增大,直径方差和速度方差减小,液滴直径和速度分布趋于集中,且变化趋势随气相流率的增大而减缓;当气相流率不变时,随液相流率的增大,液滴平均直径减小,平均速度增大,直径方差和速度方差都增大,液滴直径和速度分布趋于分散。

Singlet oxygen is the energy source of the Chemical Oxygen Iodine Laser.The reaction efficiency of singlet oxygen directly affects on the laser＇s power and the quality of light beam that COIL output.The reaction effciency depends on gas-liquid contact area.The air-liquid contact area is related to the droplet distribution in the ejector.In this article,the distribution of droplet diameter and velocity under different gas and liquid flow rate were simulated with commercial CFD software Fluent 6.3.When the liquid flow rate was unchanged,with the increasing of gas flow rate,the mean diameter of droplet was reduced and the mean droplet velocity was increased in the gas-liquid ejector.At the same time the diameter variance and velocity variance of the droplet were reduced too.The distribution of droplets＇ diameter and droplets＇ velocity trend to be concentrated.As the increasing of gas flow rate,the changing trends were slow down.When the gas flow rate was fixed,with the increasing of liquide flow rate,the mean droplet diameter was reduced and droplet velocity was increased.In the same time the diameter variance and velocity variance of the droplet were increased.The distribution of droplet diameter and droplet velocity trend to be dispersed.