Abstract: The VOF (volume of fluid) method was employed to predict the characteristic of gas-liquid two-phase flow in desalination swirl nozzle. The numerical result was compared with the experimental data and they agree with each other very well. Analyse nozzle with different nozzle diffusion angles and export diameters and we can draw conclusions that the larger diffusion angle is, the greater liquid cone angle appears and it's not the bigger the better about diffusion angle. There is an optimal value in actual application. Nozzle diffusion angle will affect the velocity of inspiratory airflow by air cone. Air cone diameter decreases with nozzle diameter decreases, and there are two skips in velocity curves. One is in just entering the nozzle position (z=0.05 m), another is between nozzle export contraction and export expansion (0.02~0.04 m). Liquid closed to the exit of nozzle accelerates more rapidly with the nozzle diameter decreases and radial velocity on the outlet section becomes larger.

Key words: VOF, Desalination, Swirl atomizer, Diffusion angle, Air cone, Export diameter

摘要： 利用VOF（volume of fluid）方法对海水淡化中空离心式喷嘴的气液两相流动进行了数值模拟，并将模拟结果与实验数据进行了对比，两者吻合良好。对喷嘴出口扩散角和出口直径等结构参数进行了比较分析，得出结论:喷嘴出口扩散角越大，喷淋液锥角度也越大，但出口扩散角度并不是越大越好，实际应用中存在一个最优值；喷嘴出口扩散角会影响到空气心吸气气流的速度大小；喷嘴中心轴线处空气心直径随着喷嘴出口直径的减小而变小，该处速度曲线有两个跃动，第一个跃动发生在刚进入喷嘴的位置（z=0.05 m），第二个跃动发生在喷嘴出口收缩段至出口扩张段（0.02~0.04 m）；喷嘴出口直径越小，对喷嘴内接近出口处液体的加速作用越明显，出口截面上的径向速度越大。

关键词: ＶＯＦ , 海水淡化 , 离心式喷嘴 , 出口扩散 , 空气心 , 出口直径