Bubble-Bubble Interaction in Horizontal Two-Phase Slug Flow

Abstract

Modelling of the slug structure requires a new effort on fundamental research. To clarify some aspects of the horizontal slug flow, an experimental study of the behaviour of two isolated bubbles in a single-phase liquid flow was performed. This procedure was adopted to avoid the overlap of different phenomena induced by a train of long bubbles. The experimental facility consists of a 90-m horizontal PVC pipe with internal diameter of 0,053 m. The behaviour of two single air bubbles travelling in a water flow was studied. Focus was given on the influence of the distance between the bubbles on the velocity of the second bubble. This study allows the understanding of the mechanism of overtaking that takes place right after the slug formation and that precedes the coalescence of bubbles in a slug flow. The results show that bubbles placed behind a liquid slug smaller than a critical value move faster than the leading one. Otherwise, they move slower than the leading one

Bubble velocity in horizontal and low-inclination upward slug flow in concentric and fully eccentric annuli

“…Here, short slugs flow at a faster velocity than the mean U B (see dashed-squared region), thus merging with the slug ahead, which consequently grows in size. However, the length of these short slugs at the location of the upstream gamma sensor is L S /D h ≈ 6.7 and 7.5 for Figure 13a and b, respectively, which is larger than the critical length found by Fagundes Netto et al (2001). Moreover, the minimum slug length for the given flow conditions in Figure 13a and b, for slugs that follow the linear trend (with values close to the mean), is L S /D h = 5.7 and 6.0, respectively.…”

“…Moissis and Griffith (1962) found that, for vertical flows, the bubble velocity decreases with an increase in L S /D until a critical L S value is reached above which the bubble velocity remains fairly constant. Fagundes Netto et al (2001) performed experiments in horizontal water flows to study the behaviour of two isolated air bubbles flowing in the test section. They found that liquid slugs with initial lengths longer than a critical value (L CRIT = 6.3D) grow in size with distance from the inlet.…”

Investigation of Taylor Bubble Behavior in Upward and Downward Vertical and Inclined Flows

“…Several models of flow distribution coefficient (C0) are reported in the literature that account for bubblebubble interaction. For example, Moissis and Griffith (1962), Barnea and Taitel (1993), Cook and Behnia (2000), Fagundes Netto et al (2001), Shemer (2003), and Mayor et al (2007 stem from the experimentally observed dependency of C0 on slug length in front of the bubble in undeveloped slug flow (Lawrence et al 2015). These models are of particular importance for slug tracking models.…”