On the role of droplets in cocurrent annular and churn-annular pipe flow

Prediction of the interfacial shear-stress in vertical annular flow

“…(1). Profiles of the mean axial velocity in vertical annular flow are shown in Van't Westende et al (2007) for a superficial gas velocity U GS of 21 m/s and superficial liquid velocities U LS of 0.01, 0.02 and 0.04 m/s, which are roughly the same conditions as some results presented here.…”

“…The value of the deposition rate R D is obtained from interpolation of the experimental results presented in Fore and Dukler (1995a), who studied a vertical annular flow in conditions similar to ours. The centerline velocity of the droplets V D is set in our work equal to the gas bulk velocity U B , which is a good estimate according to the data in Fore and Dukler (1995a,b) and Van't Westende et al (2007). We note that changing V D from 0:8 Á U B to 1:2 Á U B does not change the overall picture presented below.…”

“…The measurements are presented inVan't Westende et al (2007). The two curves for each value of ULS correspond to the profiles measured on both sides of the pipe.…”

Study of the two-phase liquid loading phenomenon by applying CFD techniques

“…Van 't Westende et al [7] studied the influence of droplets on the occurrence of liquid backflow on air-water two-phase flow in an long vertical Plexiglas tube. The experimental assembly had a gas entrance arranged at the lower end of the pipe, a liquid entrance at one meter above bottom and the top end open to the atmosphere.…”

Experimental study on the critical gas velocity of liquid-loading onset in an inclined coiled tube

“…Later, Nosseir et al (1997), Li et al (2002), Zhou and Yuan (2010) and Wang et al (2015) modified Turner's entrained droplet model based on the single liquid droplet model, which considered the effect of the flow regime, droplet deformation and liquid amount in the gas stream on the critical gas velocity. Meanwhile, investigators (Zabaras et al, 1986;Van't Westende et al, 2007;Belfroid et al, 2008;Van't Westende, 2008) noticed that the liquid loading should be characterized by the film instability, and the liquid droplet model may not be sufficient to predict the liquid-loading onset condition in a vertical gas well.…”