A new methodology was developed for the numerical simulation of transient two-phaseflow in pipes. The method combines high-resolution numerical solvers and adaptive meshrefinement (AMR) techniques, and can achieve an order of magnitude improvement incomputational time compared to solvers using conventional uniform grids.After a thorough analysis of the mathematical models used to describe the complexbehaviour of two-phase flows, the methodology was used with three specific models inorder to evaluate the robustness and accuracy of the numerical schemes developed, and toassess the ability of these models to predict two physical flow regimes, namely stratifiedand slug flows.The first stage of the validation work was to examine the physical correlations required foran accurate modelling of the stratified smooth and wavy flow patterns, and a newcombination of existing correlations for the wall and interfacial friction factors wassuggested in order to properly predict the flow features of the experimental transient caseinvestigated.The second and final phase of the work dealt with the complex and multi-dimensionalnature of slug flow. This flow regime remains a major and expensive headache for oilproducers, due to its unsteady nature and high-pressure drop. The irregular flow results inpoor oil/water separation, limits production and can cause flaring. The modellingapproached that was adopted here is based on the two-fluid model, which can theoreticallyfollows each formed slug and predicts its evolution, growth and decay, as it moves alongthe pipe.However, the slug flow study, performed here through a test case above the InviscidKelvin-Helmholtz transition from stratified to slug flow, showed that the incompressibletwo-fluid model used is unable to accurately predict most of the features of this complexflow. Mechanisms such as the interfacial wave formation, the slug growth and propagation,although observed from the simulations, cannot be accurately determined by the model.
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