Abstract:

The phenomenon of droplet impact on a single fiber is widely present in the processing of oil and gas, making the study of the spreading characteristics of droplet impact on a single fiber of significant importance for enhancing the thermal and mass transfer efficiency of chemical engineering equipment. Based on the volume of fluent (VOF) method, a numerical model of droplet impact on a single fiber was established, and the effects of initial velocity, initial diameter, impact eccentricity, and impact angle on the droplet spreading factor were systematically studied. The results indicate that increasing the initial velocity accelerates the growth rate of the spreading factor and extends the duration of its maximum value. Additionally, reducing the initial diameter of the droplet yields a higher spreading factor. Shortening the impact eccentricity facilitates more comprehensive spreading of the droplet, with the optimal spreading effect occurring at an eccentricity within 0.2R. Decreasing the impact angle also promotes more thorough spreading of the droplet, where the spreading factor curve exhibits a spreading transition point at different impact angles. Furthermore, the pressure difference between the center and sides of the liquid film drives the rapid spreading of the droplet until it stops after reaching the maximum spreading length. This study can provide a theoretical reference for the optimization design of chemical engineering equipment containing wire mesh packing.

Key words: droplet, impact, spreading factor, spreading mechanism, numerical simulation

摘要：

液滴撞击单丝现象在石油与天然气处理过程中广泛存在，研究液滴撞击单丝的铺展特性对于提高化工设备的热质传递效率有重要意义。基于VOF方法建立液滴撞击单丝的数值模型，系统研究了初始速度、初始直径、撞击偏心距、撞击角度对液滴铺展因子的影响。结果表明，增加初始速度能加快铺展因子增长速率并延长其最大铺展因子的保持时间。减小液滴的初始直径显示出更高的铺展因子；缩短撞击偏心距有助于液滴的更充分铺展，控制在0.2R以内时铺展效果最佳；减小撞击角度也可促进液滴更充分地铺展，其中铺展因子曲线在不同撞击角度下存在一个铺展转换点。此外液膜中心与两侧压差驱动液滴快速铺展，直至达到最大铺展长度后停止。研究结果可为含有丝网填料的化工设备的优化设计提供理论参考。

关键词: 液滴, 碰撞, 铺展因子, 铺展机制, 数值模拟