非均匀和均匀电场下液滴的形变及运动行为  

Deformation and Motion Behavior of Water Droplet Under Uniform and Non-uniform Electric Field

作　　者：陈庆国[1] 宋春辉[1] 梁雯[1] 刘增[2] 赵忠山[2] 魏新劳[1] 

机构地区：[1]哈尔滨理工大学工程电介质及其应用教育部重点实验室,哈尔滨150080 [2]大庆油田设计院,大庆163712

出　　处：《高电压技术》2016年第3期949-958,共10页High Voltage Engineering

基　　金：国家重点基础研究发展计划(973计划)(2012CB723308);黑龙江省科技攻关项目(GZ11A210)~~

摘　　要：电场作用下液滴形变及运动行为是电脱水机理研究的重要内容,为了研究不同电场类型下液滴的运动特性,基于相场方法建立了液滴在均匀与非均匀电场下的仿真模型,研究了油中液滴在形变、位移过程中电荷密度和电场力的分布以及液滴的聚结情况,通过实验观测分析了液滴在均匀场与非均匀场中的形变以及运动行为。研究结果表明,液滴在非均匀场中不仅发生如同在均匀场中的形变,而且会在介电泳力作用下向电场集中区域发生移动;液滴表面极化出的电荷密度以及其所受到Maxwell应力从液滴中部向两端逐渐增大,在均匀电场中对称分布在液滴两端,而在非均匀电场中靠近电场集中区域的电荷密度和Maxwell应力最大;在一定范围内提高电场强度,液滴在非均匀电场中的接触机率比均匀场中的大,受到的偶极吸引力增大,使液滴间的聚结速度大于均匀电场中的聚结速度,但过高的电场强度容易使液滴破裂。Droplet deformation and motion behavior under electric field are important contents in the research of electric dehydration mechanism. In order to research movement characteristics under different electric field types, a simulation model of droplet was established through the phase field method under uniform and non-uniform electric field. The distributions of charge density and electric field force on the droplet surface as well as the coupling effect of flow field and electric field were investigated during the process of droplet deformation, moving and coalescence. Moreover, the droplet deformation and motion behavior were simulated and analyzed under uniform and non-uniform electric field. The results show that the tensile deformation and migration of water droplets will both occur under AC non-uniform electric field. The distribution of polarization charges is different on the droplet surface under non-uniform electric field, increasing from the center to both ends of the droplet. The values of polarization charge and Maxwell stress at droplet＇s one end surface closed to electric field concentrated area are the largest. The electric field makes the surrounding fluid of water droplets to rotate and to generate different intensity flow fields, then the flow field and the dipole attraction force will both make the droplets coalescence rate faster. Within a certain range, the improvement of electric field intensity can increase collision probability and dipoalr interaction of water droplets under the non-uniform electric field when compared with uniform electric field. However, the higher strength of electric field can also make water droplets broken easily.

关 键 词：非均匀电场 相场方法 形变 介电泳 聚结 乳化液 

分 类 号：TE624.1[石油与天然气工程—油气加工工程]