An Empirical Model to Predict the Transition Between Stratified and Nonstratified Gas–Liquid Two-Phase Flow in Horizontal and Downward Inclined Pipes

Abstract

The specific objective of this work is to develop an empirical model to predict the existence of stratified flow in horizontal and downward inclined gas-liquid two-phase flow. The proposed model is in nondimensional form and attempts to emulate the qualitative trend of the Taitel and Dukler mechanistic model. The key advantage of the proposed method is that it is explicit in nature and, unlike Taitel and Dukler, it does not require use of a graphical or iterative solution. The empirical parameters used in the proposed model account for the effect of pipe diameter, pipe orientation, and the liquid density on the transition line between stratified and nonstratified flow. The accuracy of the proposed model is verified against the flow visualization data collected from more than 16 data sources consisting of 8 fluid combinations, pipe diameter in a range of 8.9 to 300 mm, liquid density in a range of 780 to 1420 kg/m 3 , and all downward pipe inclinations including horizontal.

Onset of intermittent flow: Visualization of flow structures

“…The transition line obtained on this study was compared with those proposed by Weisman et al [23] (Fig. 9a), Cheng et al [22] and Bhagwat and Ghajar [30] (Fig. 9b).…”

“…These observations, were also made by Ghajar and Tang [28], Vaze and Banerjee [29] and Thaker and Banerjee [10], contradicting those reported by Hurlburt and Hanratty [20]. Bhagwat and Ghajar [30] proposed an empirical model for the transition from stratified to non-stratified flows. This model uses the same dimensionless number as the models of Taitel and Dukler [19] and Cheng et al [22].…”

Effects of high oil viscosity on oil‐gas downward flow in deviated pipes. Part 1: Experimental setup and flow pattern transitions

“…Recently, experimental and theoretical studies focused on the analysis of the flow variables for the entire range of downward inclined two-phase flow. [17][18][19][20][21][22][23] These studies highlight the development of a flow pattern independent drift-flux model based on void fraction correlation and an empirical non-dimensional model to distinguish between stratified and non-stratified flow patterns.…”

“…The literature reviewed covers the following experimental range: pipe internal diameter (ID) 9-300 mm, liquid density (ρ L ) 780 kg/m 3 -1420 kg/m 3 , gas density (ρ G ) 1.2 kg/m 3 -35 kg/m 3 , and liquid viscosity (μ L ) 0.2 Pa Á s-80 Pa Á s. [29,30] This study presents a new set of experimental data for downward high viscosity oil-gas flow: μ L = 213 mPa s at The behaviour of the flow pattern transitions is analyzed using the experimental data, considering the concept of liquid substrate and type of waves introduced by Chu and Dukler, [24,25] and the topological structures identified by Webb and Hewitt [26] and complemented by Zadrazil and Markides. [30] The experimentally observed flow patterns were compared with the flow pattern predictions of Barnea, [9] TUFFP, [13] Bhagwat and Ghajar, [20] Taitel and Dukler, [4] and OLGA [31] models. Table 1 summarizes three stratified-annular transition models: Taitel and Dukler, [4] Barnea, [9] and Bhagwat and Ghajar [20] models.…”

“…[30] The experimentally observed flow patterns were compared with the flow pattern predictions of Barnea, [9] TUFFP, [13] Bhagwat and Ghajar, [20] Taitel and Dukler, [4] and OLGA [31] models. Table 1 summarizes three stratified-annular transition models: Taitel and Dukler, [4] Barnea, [9] and Bhagwat and Ghajar [20] models. Taitel and Dukler proposed a transition criterion between stratified (ST) and Intermittent (I) or annular-dispersed (AD) patterns for horizontal and near horizontal gas-liquid flow.…”