Simplified generalised drift velocity correlation for elongated bubbles in liquid in pipes

Abstract

Most of the existing drift velocity models have limitations, and sometimes low predictive capabilities, primarily because they are derived from experimental data which scarcely account for the combined effect of viscosity, surface tension and pipe inclination. Published data of drift velocity of elongated bubbles in pipes have been extracted from the open literature, and new data have been generated from Taylor bubble experiments conducted in a low pressure flow loop using nominal oil viscosities of 160cP and 1140cP in 0.099m and 0.057m internal diameter inclined pipes (1.0 to 7.5 degrees from horizontal). These data have been processed and a simplified generalised drift velocity correlation established. The evaluation of some existing elongated bubble rise velocity has also been carried out. The prediction of the drift velocity of a single elongated gas bubble in liquid in pipes can sometimes be overestimated by 20% or more, and sometimes be underestimated by 20% or more. It is shown that the new proposed simplified generalised correlation has an improved predictive capability when used to estimate the drift velocity of a bubble in stagnant liquid in a pipe.

Experimental Study of Single Taylor Bubble Rising in Stagnant and Downward Flowing Non-Newtonian Fluids in Inclined Pipes

“…An additional database collected from Carew et al [24], Sousa et al [28], Eghorieta et al [43], and Livinus et al [44] was applied to validate the applicability of the proposed correlation. The database is summarized in Table 3 (inclination angles are measured from vertical).…”

“…The non-Newtonian fluids (power-law) experimental data reported by Carew et al [24] and Sousa et al [28] are for different concentrations of CMC and Carbopol, covering a range of pipe diameters and liquid viscosities. The Newtonian fluids used by Eghorieta et al [43], and Livinus et al [44] were water and oil, respectively. According to the rheological model for Newtonian and power-law fluids, the apparent viscosity for a Newtonian fluid is the same as liquid viscosity; the yield point in a power-law fluid is zero.…”

Development of a multiphase lattice Boltzmann model for high-density and viscosity ratio flows in unconventional gas wells

“…The same trend as previous cases is observed in which near vertical and horizontal pipe configurations are accurately determined by the correlation, but intermediary inclinations are over-predicted.The results of inclination tests imply serious limitations and poor predictive capability of Taylor bubble velocity models. This observation agrees with the recent work of Livinus et al[216] where correlation errors of over 20% were common, even for their proposed model. The reason for such large uncertainty when predicting the velocity of these elongated bubbles comes from two primary sources.…”

Experimental study of a single elongated bubble in liquid in under 10-degree upwardly inclined pipes

“…Lizarraga-Garcia et al [22], and Livinus et al [23], have used different combinations of the dimensionless pi-groups and other set of independent dimensionless groups (e.g Reynolds number,…”

“…The new collected data of drift velocity can contribute to improve the general knowledge of pipe inclination and viscosity dependency in drift velocity correlations. Some of the outcomes have been reported in Livinus et al [23], but with little details. In addition, obtaining data on the bubble characteristics -shape, length, void fraction and drift velocity, may help for the development and validation of numerical models, including Computational Fluid Dynamics (CFD) based models.…”