Abstract

Aeration in slug and associated secondary flow leads to surging of pressure and erosion corrosion in pipe. Surging of pressure develops high mechanical impact on the pipe, and erosion corrosion reduces the thickness of internal wall, thereby resulting in pipe failure. To explore the phenomena of aeration in slug, flow visualization analysis is reported in this paper for intermittent flow sub-regimes and their transition. Analysis is reported for onset of slug, transition of plug to slug flow and development of aeration at the slug front. The visualized images and the motion pictures captured using high-speed photography in the present experiments are used to depict the process of air entrapment during the transition of wavy-stratified flow to slug flow as well as plug flow to slug flow. It is depicted for the first time through our visualization analysis that gas bubble entrapment in slug happens due to plunging kind of wave breaking mechanism. The captured images are also analyzed to describe the phenomena of augmentation of aeration in slug leading to the formation of highly aerated slug flow. Thorough understanding of aeration in slug will help in avoiding the chances of pipe failure.

Graphical abstract

中文翻译：

---

弹片中的充气物理：水平管道中的流动可视化分析

摘要

塞中的通气和相关的二次流会导致压力激增和管道中的腐蚀腐蚀。压力激增会对管道产生强烈的机械冲击，而腐蚀腐蚀会减小内壁的厚度，从而导致管道故障。为了探究弹塞中的通气现象，本文报道了间歇性流动子区域及其过渡的流动可视化分析。据报告分析了塞的发生，塞子向塞流的过渡以及塞前的通气发展。在本实验中，使用高速摄影术捕获的可视化图像和运动图像用于描述波浪状分层流向段塞流以及塞流向段塞流过渡过程中的空气截留过程。通过我们的可视化分析首次描述了，由于一种破波机制的下降，气泡被夹在塞中发生了。还对捕获的图像进行分析，以描述describe中充气增加的现象，从而导致形成高充气的流。对弹头中的通气有透彻的了解将有助于避免发生管道故障的机会。

图形概要