气泡雾化喷嘴雾化射流场性能仿真

Simulation of Spray Characteristics of Effervescent Atomizer

研究气泡雾化喷嘴外部射流场的特性问题,由于喷嘴出口处液膜破碎过程的复杂性,有时会影响雾化质量。为了提高雾化性能,提出将雾化过程细分两个子过程,利用FORTRAN语言程序计算液膜破碎过程,得出液滴初始数据,再用计算流体仿真软件Fluent,建立描述气流-液滴两相流动的合理模型,用Realizableκ-ε湍流模型与DPM离散相组合,进行二次雾化过程,并考虑气液两相间的耦合作用以及液滴破碎和碰撞模型,对雾化射流中的液滴粒径SMD沿喷嘴轴向的分布进行仿真,计算结果与实验数据进行比较吻合较好,可为雾化性能的优化提供有效的数据支持。

Atomization quality is sometimes affected by the breakup of liquid sheet downstream the spout because of its complicacy,when characteristics of the spray out of effervescent atomizer are studied.In order to improve atomization quality,we divided the atomization procedure into two sub procedures and used a FORTRAN program for the first sub procedure to get the droplet initial data.Then we built a reasonable model based on the atomization mechanism about the two-phase flow between airflow and droplets.Simulation was performed for the secondary atomization process with the realizable κ-ε model and DPM model in the software Fluent,and the coupling between airflow and droplets was taken into account.Simulation results about the droplet size distribution along the axis of the atomizer fit the experiment data well,which can provide helpful data for the performance optimization of effervescent atomizer.