绕圆柱非定常尾涡对液滴碰撞聚结影响的数值模拟

全文下载： 202101015.pdf

文章编号： 16726987（2021）01009909； DOI： 10.16351/j.16726987.2021.01.015

李涛1， 金睿珠1， 谭更彬1， 刘宇飞1， 曹兴1， 王志泉2

(1.青岛科技大学 机电工程学院，山东 青岛 266061； 2.山东省思威安全生产技术中心，山东 济南 250014)

摘要： 为了探究圆柱绕流下游非定常涡脱落对液滴的变形、聚结过程的影响，运用相场方法，建立了在圆柱绕流流场中液滴变形和聚结的二维模型。探究了在两相流圆柱绕流中，不同入口速度分布、流速以及液滴相对位置对液滴的变形及聚结的影响。结果表明：在平均速度相等的情况下，入口速度为抛物线型比定值更有利于液滴的聚结，发生聚结时间可缩短为定值的1/15。随着流速的增大，液滴对聚结效率、液滴拉伸程度也增大，流速每增大05 m·s-1，液滴发生聚结时间缩短1/5左右，但当流速大于20 m·s-1时，聚结效率趋于定值；在变形过程中，液滴的长短轴之比由477增大为800。液滴对之间的夹角从0°增大到90°时，其聚结效率越来越低，夹角每增加15°，液滴间发生碰撞聚结时间增加01 s时间，当夹角增大到90°时，液滴不会发生碰撞。

关键词： 相场方法； 圆柱绕流； 液滴变形； 聚结

中图分类号： TE 832；TE 868；U 171文献标志码： A

引用格式： 李涛， 金睿珠， 谭更彬，等. 绕圆柱非定常尾涡对液滴碰撞聚结影响的数值模拟［J］. 青岛科技大学学报(自然科学版),  2021, 42(1): 99107.

LI Tao，JIN Ruizhu，TAN Gengbin, et al. Numerical simulation of impact of unsteady wake around a cylinder on drop collision and coalescence［J］. Journal of Qingdao University of Science and Technology（Natural Science Edition),  2021, 42(1): 99107.

Numerical Simulation of Impact of Unsteady Wake Around

a Cylinder on Drop Collision and CoalescenceLI Tao1， JIN Ruizhu1， TAN Gengbin1， LIU Yufei1， CAO Xing1， WANG Zhiquan2

(1.College of Electromechanical Engineering,Qingdao University of Science and Technology,Qingdao 266061, China;

2.Shandong Siwei Technology Center of Work Safety,Jinan 250014, China)

Abstract: In order to explore the effect of the flow around the cylinder on the deformation and coalescence of the waterinoil emulsion droplets, the phase field method was used to establish a 2D model of droplet deformation and coalescence under the action of a circular flow around a cylinder. The effects of different inlet velocity distribution, flow velocity and relative position of the droplets on the deformation and coalescence of the droplets in the flow around the cylinder were explored.The results showed that：With the same average speed, the parabolic inlet speed was more conducive to coalescence of droplets than a fixed value, and the coalescence time could be shortened to 1/15 of a fixed value. With the increase of the flow velocity, the droplet′s coalescence efficiency also increased the degree of droplet stretching. For each 0.5 m·s-1 increase in flow velocity, the droplets coalesce and the time decreased by about 1/5, but when the flow velocity was greater than 20 m·s-1, coalescence efficiency tends to a fixed value; During the deformation process, the ratio of the long axis to the short axis of the droplet increased from 4.77 to 800. When the angle between the droplet pairs increased from 0° to 90°, the coalescence efficiency became lower and lower. For every 15° increase in the included angle, the collision and coalescence time between the droplets increased by 01 s. When the included angle increased to 90°, the droplets would not collide.

Key words: phase field； cylinder flow； droplet deformation； coalescence

收稿日期：  20200106

基金项目： 山东省自然科学基金项目（ZR2018PEE017）；青岛市应用基础研究计划项目（171117jch）.

作者简介： 李涛（1978—），男，副教授.