| Low liquid loading three-phase flow experiments were conducted using a 6-in ID low pressure facility. The controlled parameters include vSL, vSg, and the aqueous phase fraction. The measured flow characteristics include liquid holdup, pressure gradient, wetted wall fraction, entrainment fraction, flowing aqueous phase fraction, wave characteristics, and onset of droplet entrainment. The tests were initially conducted with tap water as the aqueous phase. Then, the same test matrix was repeated after adding 51 wt% of Monoethylene Glycol (MEG) to the aqueous phase. The changes in the mentioned flow characteristics with the given flow conditions were analyzed, and the trends were discussed. Possible effects of MEG presence on the flow characteristics were investigated.;The predictions of OLGA 7.1, TUFFP unified model, and several other models were compared with the acquired liquid holdup and pressure gradient experimental results. A sensitivity analysis for the available wettability, wall friction factor, and interfacial friction factor closure relationships, within the unified model framework, was conducted, and the best options were identified. A similar sensitivity analysis was conducted for several two-phase flow droplet entrainment fraction correlations. The correlation of Pan and Hanratty (2002) was modified in an effort to improve the entrainment fraction predictions. In addition, a simple empirical correlation was suggested to predict liquid phase entrainment fraction in three-phase flow. Available correlations for wave celerity, wave frequency, and onset of entrainment were compared with experimental data. Lastly, a correlation was proposed to predict the interfacial wave amplitude.;A mechanistic model was proposed to predict flow characteristics of three-phase stratified wavy flow in pipeline. For the gas-liquid interactions, Watson's (1989) combined momentum balance equation derivation was applied. However, the interfacial shear stress was modified using the definition of Brauner and Maron (1994), and the calculation procedure was reversed. The wave celerity was assumed as an input to the model using a closure relationship. The interfacial friction factor was one of the model's outputs. The liquid-liquid interactions were modeled using a simple energy balance equation and shift in liquid phase center of gravity calculations. The liquid phases can be separated, partially mixed, or fully mixed. The bottom aqueous film velocity was calculated using the law of the wall formulation, and was used to calculate the flowing aqueous phase fraction. The model predictions of different flow characteristics, for two or three-phase flow, were compared with available experimental data, and an acceptable agreement was observed for all cases. |
