Coalescence of dispersed phase droplet under uniform electric field
1. School of Energy and Power Engineering, Jiangsu University, Zhenjiang, Jiangsu 212013, China; 2. Postdoctoral Scientific Research Workstation, Jiehua Holdings Co., Ltd., Haining, Zhejiang 314419, China
摘要 为了探究运行参数对分散相液滴的运动、聚并过程的影响,采用VOF(volume of fluid)方法捕捉分散相与连续相的流体间界面,利用漏电介质模型模拟均匀静电场,研究了电场强度、液滴粒径、液滴表面间距和液滴相对位置(液滴中心连线与电场强度方向夹角)对处于均匀电场中离散相多液滴聚并行为的影响,通过理论分析了液滴聚并过程影响因素,并与数值计算结论进行了对比.结果表明:分散相液滴聚并效率与电场强度、液滴粒径比、液滴表面间距以及液滴的相对位置有关;随着电场强度的增加,液滴的聚并效率显著增强;随着液滴表面间距以及液滴相对角度的增大,聚并效率有所降低;液滴粒径比对聚并效率亦产生影响,当液滴粒径差距较大时,液滴的聚并效率有所降低;电场强度对聚并过程的影响较为复杂,当外加电场强度持续增大时,液滴难以发生聚并,液滴被拉长后产生破碎或者弹开现象,存在阻碍液滴聚并的临界场强.
Abstract： To explore the influence of operation parameters on the movement and coalescence of droplets, the effects of electric field intensity, droplet size, distance and relative location between two droplets on coalescence were numerically investigated by the volumeoffluid (VOF) method to track the interface and by leaky dielectric model to simulate the electric field. The factors of electric field intensity, droplet size, droplet surface spacing and droplet relative position on the droplets coalescence were analyzed theoretically and compared with the numerical results. The results indicate that the efficiency is increased with the increasing of electric field intensity and decreased with the increasing of droplet diameter ratio, distance and relative angle between two droplets. The influence of field intensity on coalescence is complicated. When the electric field intensity is large enough, the two droplets can not produce coalescence process, and the droplet is elongated or rebounded by the other droplet. There is a critical value of electric field intensity for droplets coalescence.
2018, Vol. 39 
